Hindawi Publishing CorporationInternational Journal of Antennas and PropagationVolume 2013 Article ID 747629 12 pageshttpdxdoiorg1011552013747629

Research ArticleA Small Ku-Band Polarization Tracking Active Phased Array forMobile Satellite Communications

Wei Shi12 Zuping Qian1 Jun Zhou34 Xinbo Qu2 Yang Xiang2 and Liu Hong2

1 Institute of Communication Engineering PLA University of Science and Technology Nanjing 210016 China2 Antenna Research Laboratory Nanjing Telecommunication Technology Institute Nanjing 210007 China3 State Key Laboratory of Millimeter Waves Southeast University Nanjing 210096 China4Department of Micro-systems Nanjing Electronic Device Institute Nanjing 210096 China

Correspondence should be addressed to Wei Shi sw antsinacom

Received 19 April 2013 Revised 21 September 2013 Accepted 22 September 2013

Academic Editor Z N Chen

Copyright copy 2013 Wei Shi et al This is an open access article distributed under the Creative Commons Attribution License whichpermits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

A compact polarization tracking active phased array for Ku-band mobile satellite signal reception is presented In contrastwith conventional mechanically tracking antennas the approach presented here meets the requirements of beam tracking andpolarization tracking simultaneously without any servo components The two-layer stacked square patch fed by two probes is usedas antenna element The impedance bandwidth of 16 for the element covers the operating frequency range from 1225GHz to1275GHz In the presence of mutual coupling the dimensional parameters for each element of the small 7times 7 array are optimizedduring beam scanning and polarization trackingThe compact polarization trackingmodules based on the low-temperature cofiredceramic (LTCC) system-in-package (SiP) technology are proposed A small active phased array prototype with the size of 120mm(length)times 120mm (width)times 55mm (height) is developed The measured polarization tracking patterns of the prototype are givenThe polarization tracking beam can be steered in the elevation up to 50∘The gain of no less than 160 dBi and the aperture efficiencyof more than 50 are obtained The measured and simulated polarization tracking patterns agreed well

1 Introduction

Geostationary satellite communication is widely used inmilitary and civilian fields for wide area coverage In orderto improve communication capacity Ku-band satellite com-munication system utilizes orthogonal linear polarizationtransmission in both uplink (140GHzsim145 GHz) and down-link (1225GHzsim1275GHz) for frequency reuse The mobileantenna terminals may not point to the satellite when thereis the rapid change in azimuth pitch and roll of vehiclesairplanes and ships One challenge for mobile antennaterminals in Ku-band is to avoid polarization mismatchTherefore the mobile antenna terminals in Ku-band shouldmeet the requirements of beam tracking and polarizationtracking simultaneously

Reflector or lens antenna is used most widely for itshigh efficiency and low cost [1ndash3] The beam pointing andpolarization are steered mechanically But the requirementfor low profile and high tracking speed is not easily met

The mechanically tracking array antenna of stair structurehas lower profile [4 5] but the low radiating efficiency andrelatively higher sidelobe limit its use in some applicationsThe hybrid tracking planar antenna combines mechanicaltracking in azimuth and electronic tracking in elevation [6 7]However it is difficult to integrate the mechanical servocomponents with the top surface of the vehicles airplanesand ships

This paper presents a new polarization tracking activephased array based on LTCC-SiP polarization tracking mod-ule The beam and the orientation of the linear polarizationcan be electronically steered simultaneously [8] The radiat-ing element is based on a stacked square microstrip patchorthogonally fed by two probes Each probe excites hori-zontally or vertically polarized wave Therefore the arbitrarylinear polarization can be obtained through the combinationof two orthogonal polarizations We have designed a newcompact polarization tracking module with the LTCC-SiPtechnology which can be used to reduce the height of

2 International Journal of Antennas and Propagation

Wup

Wup

Top substrate h2 1205762

Foam h3 1205763

Bottom substrate h1 1205761

Wlow

Wlow

Lprobe

Lprobe

w

w

Port Hl

l

Port V

Figure 1 Configuration of the antenna element fed by two orthogonal probes

the arrayThe phase and polarization of the radiating elementcan be electronically controlled by the phase settings of themodule

A model for the small 7 times 7 array was established usingCSTMicrowave StudioWe analyzed the impedance variationof central element during beam scanning and polarizationtracking in the presence of mutual coupling Based onthe simulated results a small polarization tracking activephased array prototype for reception in the frequency rangefrom 1225GHz to 1275GHz was developed The height ofthe array is only 55mm In the microwave chamber themeasured radiation patterns for vertical horizontal anddiagonal polarization were obtained via phase settings ofthe proposed polarization tracking modules The beam canbe electronically steered up to 50∘ in the elevation Thedeveloped prototype has the minimum gain of 160 dBi andthe aperture efficiency of 50 The measured polarizationtracking patterns and the simulated ones agree well whichdemonstrates the usefulness of the design method based onmutual coupling

2 Array Design Based on Mutual Coupling

The arbitrary linearly polarized wave can be decomposedinto vertically and horizontally polarized component withthe same phase and different amplitude Thus the radiatingelement with orthogonal dual ports radiates vertically andhorizontally polarized wave simultaneously The weightedcoefficients for the dual ports of the radiating element can

be controlled via the phase settings of polarization trackingmodule and the linear polarization of arbitrary orientationcan be obtained Thus the antenna array has the capabilityof polarization tracking without mechanical rotation of thewhole array

The cross-dipoles can be used as the radiating elementfor polarization tracking phased array [9] but the height ofthe element is 048 120582

0 The dual aperture coupled microstrip

antenna can also be used to radiate orthogonally polar-ized waves [3 7] However the coaxial connecters of themicrowave modules result in the difficulty of connectionsbetween the aperture-coupled antenna elements and themodules For low profile easy fabrication and low cost two-layer stacked square microstrip antenna with dual probesis used as radiating element as shown in Figure 1 Broadbandwidth can be obtained with electromagnetic couplingmechanism between top and bottom patches Arlon Diclad880 with 120576

119903= 22 and ℎ = 0508mm is used for top and

bottom substrates Rohacell HF51 with 120576119903= 105 and ℎ =

15mm is used for the foam With the symmetrical structureof the square patch portH and port V approximately have thesame radiation pattern and resonance frequency Thereforethe little effect of the patterns on the polarization combinationcan be neglected and the amplitude and phase weightedcoefficients of dual ports determine the final polarization ofthe radiating element

The square grid arrangement for the radiating elementsis used for the simplicity of the feed network We designed asmall 7 times 7 array shown in Figure 2 which may be equivalent

International Journal of Antennas and Propagation 3

R1 R2-2 R3-3 R4-4 R5-5

R2-1 R3-2 R4-3 R5-4 R4-4

R3-1 R4-2 R5-3 R4-3 R3-3

R4-1 R5-2 R4-2 R3-2 R2-2

R5-1 R4-1 R3-1 R2-1 R1

(a) Layout

y

xo

120593

(b) Coordinate system

Figure 2 Topology of the small array (the outermost elements with gray color indicate passive elements terminated with 50Ω matchedloads)

0

minus5

minus10

minus15

minus20

minus25

S11S12

|S11|

(dB)

0

minus5

minus10

minus15

minus20

minus30

minus25

minus35

|S12|

(dB)

100 110 120 130 140 150Frequency (dB)

Figure 3 The simulated 11987811

and 11987812

of isolated antenna element

to a large array for the center element R5-3 Thus the effectof mutual coupling on the impedance of radiating element aswell as active element pattern can be analyzedThe radiatingelements are spaced a distance of 05 120582

0 wherein 120582

0is the

wavelength in free space at 125 GHzThe outermost elementswith gray color are terminated with loads of 50Ω to formpassive elements which are used to solve the problem ofdeterioration of edge element pattern of the inner 5times5 activearray

We used software CST Microwave Studio to design theisolated radiating element Array A in Table 1 was formed by7 rows of 7 elements designed without considering mutualcoupling The structural symmetry of isolated element con-tributes to the same simulated reflection coefficients of dualports shown in Figure 3 The simulated 10 dB impedancebandwidth (|119878

11| lt minus10 dB) was found to be 16 (18 GHzsim

138 GHz) which is sufficient for Ku-band satellite receiversystem Furthermore the coupling coefficient between port

Table 1 The structural parameters for the radiating element (unitmm)

Element parameters 119882up 119882low 119908 119897 119871probe

Array A (initial design ) 75 78 14 105 04Array B (final design ) 66 79 085 105 04

H and port V is belowminus18 dBHowever the difficult challengewith the polarization tracking phased array is the mutualcoupling which will result in the variation of the portimpedance of each element during polarization tracking andbeam scanningThus the design parameters in Table 1 for theradiating element in array A may be not optimum due tothe presence of mutual coupling thereby degrading the arrayperformance

A small array model was established in CST MicrowaveStudio for mutual coupling analysis If the amplitude

4 International Journal of Antennas and Propagation

Port V

Port H

0 5 10 15 20 25 30 35 40 45 50Scan angle (deg)

minus5

minus10

minus15

minus20

minus25

minus30

Activ

e refl

ectio

n co

effici

ent (

dB)

1225 GHz125 GHz1275GHz

(a) Array A

Port V

Port H

0 5 10 15 20 25 30 35 40 45 50Scan angle (deg)

minus10

minus16

minus20

minus28

minus34

minus32

minus30

minus26

minus24

minus22

minus18

minus14

minus12

Activ

e refl

ectio

n co

effici

ent (

dB)

1225 GHz125 GHz1275GHz

(b) Array B

Figure 4 The active reflection coefficient of central element R5-3 (azimuth angle 120593 = 0∘ vertical polarization)

Port V

Port H

0 5 10 15 20 25 30 35 40 45 50Scan angle (deg)

minus5

minus10

minus15

minus20

minus25

minus30

Activ

e refl

ectio

n co

effici

ent (

dB)

1225 GHz125 GHz1275GHz

(a) Array A

Port V

Port H

0 5 10 15 20 25 30 35 40 45 50Scan angle (deg)

minus5

minus10

minus15

minus20

minus25

minus30

Activ

e refl

ectio

n co

effici

ent (

dB)

1225 GHz125 GHz1275GHz

(b) Array B

Figure 5 The active reflection coefficient of central element R5-3 (azimuth angle 120593 = 0∘ horizontal polarization)

weighted coefficients for the orthogonal ports (port Hand port V) are (1 0) (0 1) and (1 1) respectivelythe small array will radiate vertically horizontally anddiagonally polarized wave In each polarization the beamcan be steered from 0∘ to 50∘ in elevation with phase vari-ation between antenna elements The key dimensionalparameters 119882up 119882low and 119908 can be adjusted via simulationtomitigate themutual coupling effect on the variation of portimpedance during polarization tracking and beam scanningThe new parameters of radiating elements proposed for arrayB are given in Table 1 The variations of active reflection

coefficient of central element R5-3 in both array A and arrayB are given in Figures 4 5 and 6 Compared with array A theactive reflection coefficient of central element R5-3 in arrayB has been reduced generally when the polarization trackingbeam is steered in the119909119911-plane (120593 = 0∘) within the scan rangeofplusmn25∘ As the scan angle increases the performance of activereflection coefficient of array B degrades gradually whichis obvious especially for the diagonal polarization Whenthe beam is steered to 50∘ in elevation the active reflectioncoefficient of about minus7 dB in the frequency range can beachieved for port HThe gain versus scan angle of both array

International Journal of Antennas and Propagation 5

minus5

minus6

minus7

minus8

minus9

minus10

minus11

minus12

minus13

minus14

minus15

minus16

minus17

minus18

Activ

e refl

ectio

n co

effici

ent (

dB)

0 5 10 15 20 25 30 35 40 45 50Scan angle (deg)

1225 GHz125 GHz1275GHz

Port V

Port H

(a) Array A

minus6

minus8

minus10

minus12

minus14

minus16

minus18

Activ

e refl

ectio

n co

effici

ent (

dB)

0 5 10 15 20 25 30 35 40 45 50Scan angle (deg)

1225 GHz125 GHz1275GHz

Port V

Port H

(b) Array B

Figure 6 The active reflection coefficient of central element R5-3 (azimuth angle 120593 = 0∘ diagonal polarization)

A and array B was computed for comparison The simulatedresults for three typical polarizations are shown in Figure 7The gain improvement for array B can be observed

As shown in Figure 8 a small 7 times 7 element array wasfabricated based on the dimensional parameters of array BThe active element patterns of central element R5-3 weremeasured when all of the other ports except for port V wereterminated with passive loads of 50Ω With reference toFigure 2 the 119909119911-plane (120593 = 0∘) is the H-plane for port V andthe 119910119911-plane (120593 = 90∘) is the E-planeThe active element pat-terns of central element R5-3 in H- and E-planes are given inFigure 9 In the area of the main lobe the agreement betweenthe simulated and measured results can be observed Boththe simulated and measured results indicate the half-powerbeamwidth of approximately 120∘ and 112∘ in the H-planeand the E-plane respectively No blind spot is observed Dueto the approximate symmetry in structure the active elementpattern of port H has the similarity with that of port V

3 Polarization Tracking Module

The polarization tracking modules are key components forthe polarization tracking active phased array The dualinput ports shown in Figure 10(b) are connected to theorthogonal dual ports of antenna element The dual inputsfrom port V and port H can be combined into singleoutput in phase via differential phase setting Δ120593 Thus thepolarization mismatch with incoming wave from satellitecan be avoided Figure 10(a) shows the coordinate sys-tem based on the unit vectors of orthogonal polarizationswherein 997888V and

997888

ℎ denote the vertical and horizontal polar-izations respectively The orientation of polarization for theincoming wave is denoted by 997888119901 and the included angleformed by 997888119901 and 997888V is denoted by 997888120572 If we neglect the

effects of radiation patterns of dual ports the inputs of theLange coupler are obtained as follows

PortC

1199063= 119886radic119866amp cos120572 (1a)

PortD

1199064= 119886radic119866amp sin120572 (1b)

wherein 119866amp is the gain of the LNA Assuming that the twochannels are consistent the signal at the output of the receivermodule can be yielded as

119906119888=

119886

2radic119871119879

radic119866amp exp [119895 (180∘

minus 120572 + 1205930)]

+

119886

2radic119871119879

radic119866amp exp [119895 (90∘

+ 1205930+ Δ120593 + 120572)]

(2)

Herein 119871119879is the average insertion loss in each channel

If the phase factor in (2) satisfies the condition as follows

Δ120593 = 90∘

minus 2120572 (3)

the combined signal has no polarization mismatch loss Inthis case the maximum combined signal is given as

119906119888=

119886

radic119871119879

radic119866amp exp [119895 (180∘

minus 120572 + 1205930)] (4)

Based on LTCC technology a vertical transition fromcoplanar waveguide to stripline is presented to reduce thesize of the module [10] Figure 11 shows the vertical transitionconfiguration and fabricated prototype The simulated and

6 International Journal of Antennas and Propagation

190

185

180

175

170

165

Gai

n (d

Bi)

minus10 0 10 20 30 40 50 60Scan angle (deg)

Array B (final design)Array A (initial design)

(a) Horizontal polarization

190

185

180

175

170

Gai

n (d

Bi)

minus10 0 10 20 30 40 50 60Scan angle (deg)

Array B (final design)Array A (initial design)

(b) Vertical polarization

190

185

180

175

170

Gai

n (d

Bi)

minus10 0 10 20 30 40 50 60Scan angle (deg)

Array B (final design)Array A (initial design)

(c) Diagonal polarization

Figure 7 The comparison of gain during polarization tracking and beam scanning (azimuth angle 120593 = 0∘)

Figure 8 Front view of the fabricated array

International Journal of Antennas and Propagation 7

50

minus5

minus10

minus15

minus20

minus25

minus30

minus35

minus40

minus45

minus50

minus55

minus60

Relat

ive a

mpl

itude

(dB)

MeasuredSimulated

minus180 minus120 minus60 0 60 120 180Angle (deg)

(a) 120593 = 0∘ (H-plane)

50

minus5

minus10

minus15

minus20

minus25

minus30

minus35

minus40

minus45

minus50

Relat

ive a

mpl

itude

(dB)

MeasuredSimulated

minus180 minus120 minus60 0 60 120 180Angle (deg)

(b) 120593 = 90∘ (E-plane)

Figure 9 The active element pattern of central element R5-3 fed from port V

120572

p

h

(a) Polarization decomposition

Receiving element

Port VPort H

LNA 2LNA 1

Lange coupler

1205930 1205930 + Δ120593

Power combiner

1 2

3 4

(b) Schematic block diagram

Figure 10 The polarization tracking module for receiving application

Ground

Coplanar waveguide

Metalized via LTCC

OutputInput

Motherboard

Stripline

(a) Schematic diagram (b) Prototype

Figure 11 Transition from planar waveguide to stripline based on LTCC technology

8 International Journal of Antennas and Propagation

0

minus15

minus30

minus45

minus60

|S11|

(dB)

0 2 4 6 8 10 12 14 16 18Frequency (GHz)

00

minus25

minus50

minus75

minus100

Inse

rtio

n lo

ss (d

B)

MeasuredSimulated

Figure 12 Reflection coefficient and insertion loss of the LTCC-based vertical transition

(a) Top view (b) Bottom view

Figure 13 The fabricated compact polarization tracking module

measured reflection coefficient and insertion loss are plottedin Figure 12 It is observed that good agreement can beobtained between the simulated and measured results from2GHz to 18GHzThemeasured reflection coefficient is belowminus16 dB and the insertion loss is less than 15 dB We usedthe compact structure of the vertical transition to developa polarization tracking module integrated with multipleMMICs which is shown in Figure 13 With reference toFigure 10(b) the gain of two channels of the module wasmeasured with 120593

0= 0∘ when Δ120593 was increased from 0∘ to

minus360∘ with a step of minus5625∘ With reference to Figure 14the measured gain of both channels varies in the range fromabout 10 dB to 35 dBwith different trend which is determinedby the differential phase Δ120593 between two channels Thusthe different amplitude weighted coefficients for both port Vand port H can be achieved which results in the arbitrarylinear polarization of the antenna element With referenceto Figure 14 the diagonal polarization (120572 = 45∘ and 120572 =minus45∘) can be obtained due to the approximately same gain

of both channels with Δ120593 = 0∘ and minus180∘ The approximatevertical polarization can be obtained with Δ120593 = minus90∘ whenthe measured gains of port H and port V are about 105 dBand 337 dB The approximate horizontal polarization can beobtained with Δ120593 = minus270∘ when the measured gains of portH and port V are about 342 dB and 105 dB

4 Experiment Result

A small 7 times 7 polarization tracking active phased arraywas fabricated to cover the frequency range from 1225GHzto 1275GHz The inner 5 times 5 radiating elements are con-nected to the polarization tracking modules discussed aboveThe miniature 50Ω SMP female terminations are used asmatched loads directly connecting to the outermost 24passive radiating elements The schematic block diagram ofthe fabricated array is shown in Figure 15 The compact-ness of the polarization tracking module based on LTCC-SiP technology contributes to the low-profile phased arraywith the size of 120mm (length)times 120mm (width) times 55mm(height) The polarization tracking patterns were measuredin 119909119911-planeThe antenna prototype to be measured was fixedon the rotary platform in the microwave chamber and thepolarization can be controlled electronically without rotatingthe array aperture The patterns for horizontal vertical anddiagonal polarization can be measured respectively withΔ120593 = minus270

∘

minus90∘ and 0∘ The narrow bandwidth of

4 determines the stable radiation patterns over the entireoperating frequency range from 1225GHz to 1275GHzThus the polarization tracking patternsmeasured at 125GHzwith beam scanned to 0∘ 20∘ 40∘ and 50∘ are given inFigures 16 17 18 and 19 The reasonable agreement between

International Journal of Antennas and Propagation 9

40

35

30

25

20

15

10

5

Differential phase (deg)

Gai

n (d

B)

Port HPort V

0 minus45 minus90 minus135 minus180 minus225 minus270 minus315 minus360

Figure 14 The measured transmission gain versus the differential phase Δ120593 for port H and port V

Polarizationtrackingmodule

Polarizationtrackingmodule

Polarizationtrackingmodule

Polarizationtrackingmodule

Polarizationtrackingmodule

Power combiner network

Beam and polarizationcontroller

Antenna array

middot middot middot

middot middot middot

middot middot middot

Figure 15 The schematic block diagram of the fabricated polarization tracking active phased array

minus90

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minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB) 20 20

(a) Horizontal polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB) 20 20

(b) Vertical polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

MeasuredSimulated

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB) 20 20

(c) Diagonal polarization

Figure 16 The polarization tracking patterns measured at 125 GHz with beam scanned to 0∘

10 International Journal of Antennas and Propagation

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

(a) Horizontal polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB) 3

(b) Vertical polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

MeasuredSimulated

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

(c) Diagonal polarization

Figure 17 The polarization tracking patterns measured at 125 GHz with beam scanned to 20∘

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

0

0

minus60

minus50minus40

minus3020

3040

5060

7

8

(a) Horizontal polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

4

(b) Vertical polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

MeasuredSimulated

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

40

(c) Diagonal polarization

Figure 18 The polarization tracking patterns measured at 125 GHz with beam scanned to 40∘

the simulated and measured results can be observed Thesummary of the antenna prototype performance measured at125 GHz is provided in Table 2 wherein H V and D denotehorizontal vertical and diagonal polarization It is found thatthe mutual coupling results in the sidelobe level are greaterthan minus10 dB when the beam is steered to the angle greaterthan 40∘ Furthermore the beamwidth and beam pointingerror increase Table 2 gives the measured peak gain of the

polarization tracking array prototype during beam scanningand polarization tracking Compared with the simulatedresults small errors exist Since there are actually 5 times 5 activeradiating elements in the small 7 times 7 array the maximumdirectivity of the array is approximately 189 dBi Thus theaperture efficiency greater than 50 for the polarizationtracking array prototype can be evaluated according to themeasured peak gain

International Journal of Antennas and Propagation 11

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

50

(a) Horizontal polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

5

(b) Vertical polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

MeasuredSimulated

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

50

(c) Diagonal polarization

Figure 19 The polarization tracking patterns measured at 125 GHz with beam scanned to 50∘

Table 2 The measured data at 125 GHz for the developed small phased array prototype

Desired scan angle (deg) 0∘ 20∘ 40∘ 50∘

H V D H V D H V D H V DPeak gain (dBi)

Simulated 187 187 187 184 185 185 177 179 179 169 175 173Measured 183 185 182 179 177 180 172 174 175 161 163 162

Aperture efficiency () 87 91 85 79 76 81 68 71 72 52 55 53SLL (dB) minus133 minus118 minus113 minus123 minus133 minus106 minus113 minus84 minus60 minus79 minus88 minus74Half-power beam width (deg) 222∘ 213∘ 216∘ 219∘ 237 222∘ 243∘ 252∘ 243∘ 264∘ 249∘ 255∘

Beam pointing error (deg) 0 minus12∘ 3∘ minus14∘ 22∘ minus14∘ minus34∘ minus34∘ minus16∘ minus41∘ minus59∘ 13∘

5 Conclusion

We propose a compact polarization tracking active phasedarray for Ku-band satellite communicationThe phased arraywith the height of 55mm is suited to be used in the applicationstrictly limiting the profile of the antenna Based on thesimulated single radiating element a small 7 times 7 array modelwas established with the simulation tool CST MicrowaveStudio The outermost 24 elements are connected to 50Ωpassive loads which contributes to the 5 times 5 active array Thewhole array was simulated and the effects of mutual couplingon the impedance of the ports can be analyzed Based onthe dimensional parameters of the isolated antenna elementthe parameters were adjusted via numerous simulations Thefinal design with mutual coupling considered had loweractive reflection coefficient of minus15 dB with beam pointed tothe boresight of the array When the array operates in thestates of horizontal vertical and diagonal polarization thesimulated active reflection coefficients versus the scan anglefor central element are plotted Furthermore we propose a

compact LTCC-based polarization trackingmodule based ona vertical transition from planar waveguide to stripline Inthe frequency range from 1225GHz to 1275GHz a smallpolarization tracking active phased array prototypewas fabri-cated and its polarization can be configured electronically viathe proposed modules The measured polarization trackingpatterns for horizontal vertical and diagonal polarization aregiven It can be found from the measurement that the beamcan be steered up to 50∘ in the elevation and the peak gain ismore than 160 dBiThe aperture efficiency of more than 50can be obtained The experiment validates the availability ofthe array design with mutual coupling considered

References

[1] S Yamamoto S Nuimura T Mizuno and Y Inasawa ldquoA Kuband small reflector antenna using backfire primary radiator forsatellite communication system on board vesselrdquo in Proceedingsof the International Symposium on Antennas and Propagation(ISAP rsquo12) pp 1273ndash1276 Nagoya Japan October 2012

12 International Journal of Antennas and Propagation

[2] J Thornton A White and G Long ldquoMulti-beam scanninglens antenna for satellite communications to trainsrdquoMicrowaveJournal vol 52 no 8 pp 56ndash70 2009

[3] A RWeily andNNikolic ldquoDual-polarized planar feed for low-profile hemispherical Luneburg lens antennasrdquo IEEE Transac-tions on Antennas and Propagation vol 60 no 1 pp 402ndash4072012

[4] S H Son and U H Park ldquoSidelobe reduction of low-profilearray antenna using a genetic algorithmrdquo ETRI Journal vol 29no 1 pp 95ndash98 2007

[5] PMousaviM Fakharzadeh S H Jamali et al ldquoA low-cost ultralow profile phased array system for mobile satellite receptionusing zero-knowledge beamforming algorithmrdquo IEEE Transac-tions on Antennas and Propagation vol 56 no 12 pp 3667ndash3679 2008

[6] S Vaccaro F Tiezzi M F Rua and C D G De Oro ldquoKu-BandLow-Profile Rx-only and Tx-Rx antennas for mobile satellitecommunicationsrdquo in Proceedings of the 4th IEEE InternationalSymposium on Phased Array Systems and Technology (Array rsquo10)pp 536ndash542 Waltham Mass USA October 2010

[7] R V Gatti L Marcaccioli E Sbarra and R SorrentinoldquoFlat array antennas for Ku-band mobile satellite terminalsrdquoInternational Journal of Antennas and Propagation vol 2009Article ID 836074 5 pages 2009

[8] C O Adler A D Monk D N Rasmussen and M J TaylorldquoTwo-way airborne broadband communications using phasedarray antennasrdquo in Proceedings of the IEEE Aerospace Confer-ence vol 2 pp 925ndash922 March 2003

[9] S Hasegawa T Yasuzumi O Hashimoto and Y KazamaldquoPolarization tracking phased array antenna with cross dipoleantenna-measured resultsrdquo in Proceedings of the IEEE Inter-national Symposium on Antennas and Propagation TorontoCanada July 2010

[10] J Zhou W Shi W B Dou and Y Shen ldquoHigh integratedmicrowave architecture using LTCC-SIP technology in activephased array antenna applicationsrdquo Frequenz vol 66 pp 177ndash182 2012

International Journal of

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International Journal of

2 International Journal of Antennas and Propagation

Wup

Wup

Top substrate h2 1205762

Foam h3 1205763

Bottom substrate h1 1205761

Wlow

Wlow

Lprobe

Lprobe

w

w

Port Hl

l

Port V

Figure 1 Configuration of the antenna element fed by two orthogonal probes

the arrayThe phase and polarization of the radiating elementcan be electronically controlled by the phase settings of themodule

A model for the small 7 times 7 array was established usingCSTMicrowave StudioWe analyzed the impedance variationof central element during beam scanning and polarizationtracking in the presence of mutual coupling Based onthe simulated results a small polarization tracking activephased array prototype for reception in the frequency rangefrom 1225GHz to 1275GHz was developed The height ofthe array is only 55mm In the microwave chamber themeasured radiation patterns for vertical horizontal anddiagonal polarization were obtained via phase settings ofthe proposed polarization tracking modules The beam canbe electronically steered up to 50∘ in the elevation Thedeveloped prototype has the minimum gain of 160 dBi andthe aperture efficiency of 50 The measured polarizationtracking patterns and the simulated ones agree well whichdemonstrates the usefulness of the design method based onmutual coupling

2 Array Design Based on Mutual Coupling

The arbitrary linearly polarized wave can be decomposedinto vertically and horizontally polarized component withthe same phase and different amplitude Thus the radiatingelement with orthogonal dual ports radiates vertically andhorizontally polarized wave simultaneously The weightedcoefficients for the dual ports of the radiating element can

be controlled via the phase settings of polarization trackingmodule and the linear polarization of arbitrary orientationcan be obtained Thus the antenna array has the capabilityof polarization tracking without mechanical rotation of thewhole array

The cross-dipoles can be used as the radiating elementfor polarization tracking phased array [9] but the height ofthe element is 048 120582

0 The dual aperture coupled microstrip

antenna can also be used to radiate orthogonally polar-ized waves [3 7] However the coaxial connecters of themicrowave modules result in the difficulty of connectionsbetween the aperture-coupled antenna elements and themodules For low profile easy fabrication and low cost two-layer stacked square microstrip antenna with dual probesis used as radiating element as shown in Figure 1 Broadbandwidth can be obtained with electromagnetic couplingmechanism between top and bottom patches Arlon Diclad880 with 120576

119903= 22 and ℎ = 0508mm is used for top and

bottom substrates Rohacell HF51 with 120576119903= 105 and ℎ =

15mm is used for the foam With the symmetrical structureof the square patch portH and port V approximately have thesame radiation pattern and resonance frequency Thereforethe little effect of the patterns on the polarization combinationcan be neglected and the amplitude and phase weightedcoefficients of dual ports determine the final polarization ofthe radiating element

The square grid arrangement for the radiating elementsis used for the simplicity of the feed network We designed asmall 7 times 7 array shown in Figure 2 which may be equivalent

International Journal of Antennas and Propagation 3

R1 R2-2 R3-3 R4-4 R5-5

R2-1 R3-2 R4-3 R5-4 R4-4

R3-1 R4-2 R5-3 R4-3 R3-3

R4-1 R5-2 R4-2 R3-2 R2-2

R5-1 R4-1 R3-1 R2-1 R1

(a) Layout

y

xo

120593

(b) Coordinate system

Figure 2 Topology of the small array (the outermost elements with gray color indicate passive elements terminated with 50Ω matchedloads)

0

minus5

minus10

minus15

minus20

minus25

S11S12

|S11|

(dB)

0

minus5

minus10

minus15

minus20

minus30

minus25

minus35

|S12|

(dB)

100 110 120 130 140 150Frequency (dB)

Figure 3 The simulated 11987811

and 11987812

of isolated antenna element

to a large array for the center element R5-3 Thus the effectof mutual coupling on the impedance of radiating element aswell as active element pattern can be analyzedThe radiatingelements are spaced a distance of 05 120582

0 wherein 120582

0is the

wavelength in free space at 125 GHzThe outermost elementswith gray color are terminated with loads of 50Ω to formpassive elements which are used to solve the problem ofdeterioration of edge element pattern of the inner 5times5 activearray

We used software CST Microwave Studio to design theisolated radiating element Array A in Table 1 was formed by7 rows of 7 elements designed without considering mutualcoupling The structural symmetry of isolated element con-tributes to the same simulated reflection coefficients of dualports shown in Figure 3 The simulated 10 dB impedancebandwidth (|119878

11| lt minus10 dB) was found to be 16 (18 GHzsim

138 GHz) which is sufficient for Ku-band satellite receiversystem Furthermore the coupling coefficient between port

Table 1 The structural parameters for the radiating element (unitmm)

Element parameters 119882up 119882low 119908 119897 119871probe

Array A (initial design ) 75 78 14 105 04Array B (final design ) 66 79 085 105 04

H and port V is belowminus18 dBHowever the difficult challengewith the polarization tracking phased array is the mutualcoupling which will result in the variation of the portimpedance of each element during polarization tracking andbeam scanningThus the design parameters in Table 1 for theradiating element in array A may be not optimum due tothe presence of mutual coupling thereby degrading the arrayperformance

A small array model was established in CST MicrowaveStudio for mutual coupling analysis If the amplitude

4 International Journal of Antennas and Propagation

Port V

Port H

0 5 10 15 20 25 30 35 40 45 50Scan angle (deg)

minus5

minus10

minus15

minus20

minus25

minus30

Activ

e refl

ectio

n co

effici

ent (

dB)

1225 GHz125 GHz1275GHz

(a) Array A

Port V

Port H

0 5 10 15 20 25 30 35 40 45 50Scan angle (deg)

minus10

minus16

minus20

minus28

minus34

minus32

minus30

minus26

minus24

minus22

minus18

minus14

minus12

Activ

e refl

ectio

n co

effici

ent (

dB)

1225 GHz125 GHz1275GHz

(b) Array B

Figure 4 The active reflection coefficient of central element R5-3 (azimuth angle 120593 = 0∘ vertical polarization)

Port V

Port H

0 5 10 15 20 25 30 35 40 45 50Scan angle (deg)

minus5

minus10

minus15

minus20

minus25

minus30

Activ

e refl

ectio

n co

effici

ent (

dB)

1225 GHz125 GHz1275GHz

(a) Array A

Port V

Port H

0 5 10 15 20 25 30 35 40 45 50Scan angle (deg)

minus5

minus10

minus15

minus20

minus25

minus30

Activ

e refl

ectio

n co

effici

ent (

dB)

1225 GHz125 GHz1275GHz

(b) Array B

Figure 5 The active reflection coefficient of central element R5-3 (azimuth angle 120593 = 0∘ horizontal polarization)

weighted coefficients for the orthogonal ports (port Hand port V) are (1 0) (0 1) and (1 1) respectivelythe small array will radiate vertically horizontally anddiagonally polarized wave In each polarization the beamcan be steered from 0∘ to 50∘ in elevation with phase vari-ation between antenna elements The key dimensionalparameters 119882up 119882low and 119908 can be adjusted via simulationtomitigate themutual coupling effect on the variation of portimpedance during polarization tracking and beam scanningThe new parameters of radiating elements proposed for arrayB are given in Table 1 The variations of active reflection

coefficient of central element R5-3 in both array A and arrayB are given in Figures 4 5 and 6 Compared with array A theactive reflection coefficient of central element R5-3 in arrayB has been reduced generally when the polarization trackingbeam is steered in the119909119911-plane (120593 = 0∘) within the scan rangeofplusmn25∘ As the scan angle increases the performance of activereflection coefficient of array B degrades gradually whichis obvious especially for the diagonal polarization Whenthe beam is steered to 50∘ in elevation the active reflectioncoefficient of about minus7 dB in the frequency range can beachieved for port HThe gain versus scan angle of both array

International Journal of Antennas and Propagation 5

minus5

minus6

minus7

minus8

minus9

minus10

minus11

minus12

minus13

minus14

minus15

minus16

minus17

minus18

Activ

e refl

ectio

n co

effici

ent (

dB)

0 5 10 15 20 25 30 35 40 45 50Scan angle (deg)

1225 GHz125 GHz1275GHz

Port V

Port H

(a) Array A

minus6

minus8

minus10

minus12

minus14

minus16

minus18

Activ

e refl

ectio

n co

effici

ent (

dB)

0 5 10 15 20 25 30 35 40 45 50Scan angle (deg)

1225 GHz125 GHz1275GHz

Port V

Port H

(b) Array B

Figure 6 The active reflection coefficient of central element R5-3 (azimuth angle 120593 = 0∘ diagonal polarization)

A and array B was computed for comparison The simulatedresults for three typical polarizations are shown in Figure 7The gain improvement for array B can be observed

As shown in Figure 8 a small 7 times 7 element array wasfabricated based on the dimensional parameters of array BThe active element patterns of central element R5-3 weremeasured when all of the other ports except for port V wereterminated with passive loads of 50Ω With reference toFigure 2 the 119909119911-plane (120593 = 0∘) is the H-plane for port V andthe 119910119911-plane (120593 = 90∘) is the E-planeThe active element pat-terns of central element R5-3 in H- and E-planes are given inFigure 9 In the area of the main lobe the agreement betweenthe simulated and measured results can be observed Boththe simulated and measured results indicate the half-powerbeamwidth of approximately 120∘ and 112∘ in the H-planeand the E-plane respectively No blind spot is observed Dueto the approximate symmetry in structure the active elementpattern of port H has the similarity with that of port V

3 Polarization Tracking Module

The polarization tracking modules are key components forthe polarization tracking active phased array The dualinput ports shown in Figure 10(b) are connected to theorthogonal dual ports of antenna element The dual inputsfrom port V and port H can be combined into singleoutput in phase via differential phase setting Δ120593 Thus thepolarization mismatch with incoming wave from satellitecan be avoided Figure 10(a) shows the coordinate sys-tem based on the unit vectors of orthogonal polarizationswherein 997888V and

997888

ℎ denote the vertical and horizontal polar-izations respectively The orientation of polarization for theincoming wave is denoted by 997888119901 and the included angleformed by 997888119901 and 997888V is denoted by 997888120572 If we neglect the

effects of radiation patterns of dual ports the inputs of theLange coupler are obtained as follows

PortC

1199063= 119886radic119866amp cos120572 (1a)

PortD

1199064= 119886radic119866amp sin120572 (1b)

wherein 119866amp is the gain of the LNA Assuming that the twochannels are consistent the signal at the output of the receivermodule can be yielded as

119906119888=

119886

2radic119871119879

radic119866amp exp [119895 (180∘

minus 120572 + 1205930)]

+

119886

2radic119871119879

radic119866amp exp [119895 (90∘

+ 1205930+ Δ120593 + 120572)]

(2)

Herein 119871119879is the average insertion loss in each channel

If the phase factor in (2) satisfies the condition as follows

Δ120593 = 90∘

minus 2120572 (3)

the combined signal has no polarization mismatch loss Inthis case the maximum combined signal is given as

119906119888=

119886

radic119871119879

radic119866amp exp [119895 (180∘

minus 120572 + 1205930)] (4)

Based on LTCC technology a vertical transition fromcoplanar waveguide to stripline is presented to reduce thesize of the module [10] Figure 11 shows the vertical transitionconfiguration and fabricated prototype The simulated and

6 International Journal of Antennas and Propagation

190

185

180

175

170

165

Gai

n (d

Bi)

minus10 0 10 20 30 40 50 60Scan angle (deg)

Array B (final design)Array A (initial design)

(a) Horizontal polarization

190

185

180

175

170

Gai

n (d

Bi)

minus10 0 10 20 30 40 50 60Scan angle (deg)

Array B (final design)Array A (initial design)

(b) Vertical polarization

190

185

180

175

170

Gai

n (d

Bi)

minus10 0 10 20 30 40 50 60Scan angle (deg)

Array B (final design)Array A (initial design)

(c) Diagonal polarization

Figure 7 The comparison of gain during polarization tracking and beam scanning (azimuth angle 120593 = 0∘)

Figure 8 Front view of the fabricated array

International Journal of Antennas and Propagation 7

50

minus5

minus10

minus15

minus20

minus25

minus30

minus35

minus40

minus45

minus50

minus55

minus60

Relat

ive a

mpl

itude

(dB)

MeasuredSimulated

minus180 minus120 minus60 0 60 120 180Angle (deg)

(a) 120593 = 0∘ (H-plane)

50

minus5

minus10

minus15

minus20

minus25

minus30

minus35

minus40

minus45

minus50

Relat

ive a

mpl

itude

(dB)

MeasuredSimulated

minus180 minus120 minus60 0 60 120 180Angle (deg)

(b) 120593 = 90∘ (E-plane)

Figure 9 The active element pattern of central element R5-3 fed from port V

120572

p

h

(a) Polarization decomposition

Receiving element

Port VPort H

LNA 2LNA 1

Lange coupler

1205930 1205930 + Δ120593

Power combiner

1 2

3 4

(b) Schematic block diagram

Figure 10 The polarization tracking module for receiving application

Ground

Coplanar waveguide

Metalized via LTCC

OutputInput

Motherboard

Stripline

(a) Schematic diagram (b) Prototype

Figure 11 Transition from planar waveguide to stripline based on LTCC technology

8 International Journal of Antennas and Propagation

0

minus15

minus30

minus45

minus60

|S11|

(dB)

0 2 4 6 8 10 12 14 16 18Frequency (GHz)

00

minus25

minus50

minus75

minus100

Inse

rtio

n lo

ss (d

B)

MeasuredSimulated

Figure 12 Reflection coefficient and insertion loss of the LTCC-based vertical transition

(a) Top view (b) Bottom view

Figure 13 The fabricated compact polarization tracking module

measured reflection coefficient and insertion loss are plottedin Figure 12 It is observed that good agreement can beobtained between the simulated and measured results from2GHz to 18GHzThemeasured reflection coefficient is belowminus16 dB and the insertion loss is less than 15 dB We usedthe compact structure of the vertical transition to developa polarization tracking module integrated with multipleMMICs which is shown in Figure 13 With reference toFigure 10(b) the gain of two channels of the module wasmeasured with 120593

0= 0∘ when Δ120593 was increased from 0∘ to

minus360∘ with a step of minus5625∘ With reference to Figure 14the measured gain of both channels varies in the range fromabout 10 dB to 35 dBwith different trend which is determinedby the differential phase Δ120593 between two channels Thusthe different amplitude weighted coefficients for both port Vand port H can be achieved which results in the arbitrarylinear polarization of the antenna element With referenceto Figure 14 the diagonal polarization (120572 = 45∘ and 120572 =minus45∘) can be obtained due to the approximately same gain

of both channels with Δ120593 = 0∘ and minus180∘ The approximatevertical polarization can be obtained with Δ120593 = minus90∘ whenthe measured gains of port H and port V are about 105 dBand 337 dB The approximate horizontal polarization can beobtained with Δ120593 = minus270∘ when the measured gains of portH and port V are about 342 dB and 105 dB

4 Experiment Result

A small 7 times 7 polarization tracking active phased arraywas fabricated to cover the frequency range from 1225GHzto 1275GHz The inner 5 times 5 radiating elements are con-nected to the polarization tracking modules discussed aboveThe miniature 50Ω SMP female terminations are used asmatched loads directly connecting to the outermost 24passive radiating elements The schematic block diagram ofthe fabricated array is shown in Figure 15 The compact-ness of the polarization tracking module based on LTCC-SiP technology contributes to the low-profile phased arraywith the size of 120mm (length)times 120mm (width) times 55mm(height) The polarization tracking patterns were measuredin 119909119911-planeThe antenna prototype to be measured was fixedon the rotary platform in the microwave chamber and thepolarization can be controlled electronically without rotatingthe array aperture The patterns for horizontal vertical anddiagonal polarization can be measured respectively withΔ120593 = minus270

∘

minus90∘ and 0∘ The narrow bandwidth of

4 determines the stable radiation patterns over the entireoperating frequency range from 1225GHz to 1275GHzThus the polarization tracking patternsmeasured at 125GHzwith beam scanned to 0∘ 20∘ 40∘ and 50∘ are given inFigures 16 17 18 and 19 The reasonable agreement between

International Journal of Antennas and Propagation 9

40

35

30

25

20

15

10

5

Differential phase (deg)

Gai

n (d

B)

Port HPort V

0 minus45 minus90 minus135 minus180 minus225 minus270 minus315 minus360

Figure 14 The measured transmission gain versus the differential phase Δ120593 for port H and port V

Polarizationtrackingmodule

Polarizationtrackingmodule

Polarizationtrackingmodule

Polarizationtrackingmodule

Polarizationtrackingmodule

Power combiner network

Beam and polarizationcontroller

Antenna array

middot middot middot

middot middot middot

middot middot middot

Figure 15 The schematic block diagram of the fabricated polarization tracking active phased array

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB) 20 20

(a) Horizontal polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB) 20 20

(b) Vertical polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

MeasuredSimulated

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB) 20 20

(c) Diagonal polarization

Figure 16 The polarization tracking patterns measured at 125 GHz with beam scanned to 0∘

10 International Journal of Antennas and Propagation

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

(a) Horizontal polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB) 3

(b) Vertical polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

MeasuredSimulated

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

(c) Diagonal polarization

Figure 17 The polarization tracking patterns measured at 125 GHz with beam scanned to 20∘

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

0

0

minus60

minus50minus40

minus3020

3040

5060

7

8

(a) Horizontal polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

4

(b) Vertical polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

MeasuredSimulated

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

40

(c) Diagonal polarization

Figure 18 The polarization tracking patterns measured at 125 GHz with beam scanned to 40∘

the simulated and measured results can be observed Thesummary of the antenna prototype performance measured at125 GHz is provided in Table 2 wherein H V and D denotehorizontal vertical and diagonal polarization It is found thatthe mutual coupling results in the sidelobe level are greaterthan minus10 dB when the beam is steered to the angle greaterthan 40∘ Furthermore the beamwidth and beam pointingerror increase Table 2 gives the measured peak gain of the

polarization tracking array prototype during beam scanningand polarization tracking Compared with the simulatedresults small errors exist Since there are actually 5 times 5 activeradiating elements in the small 7 times 7 array the maximumdirectivity of the array is approximately 189 dBi Thus theaperture efficiency greater than 50 for the polarizationtracking array prototype can be evaluated according to themeasured peak gain

International Journal of Antennas and Propagation 11

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

50

(a) Horizontal polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

5

(b) Vertical polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

MeasuredSimulated

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

50

(c) Diagonal polarization

Figure 19 The polarization tracking patterns measured at 125 GHz with beam scanned to 50∘

Table 2 The measured data at 125 GHz for the developed small phased array prototype

Desired scan angle (deg) 0∘ 20∘ 40∘ 50∘

H V D H V D H V D H V DPeak gain (dBi)

Simulated 187 187 187 184 185 185 177 179 179 169 175 173Measured 183 185 182 179 177 180 172 174 175 161 163 162

Aperture efficiency () 87 91 85 79 76 81 68 71 72 52 55 53SLL (dB) minus133 minus118 minus113 minus123 minus133 minus106 minus113 minus84 minus60 minus79 minus88 minus74Half-power beam width (deg) 222∘ 213∘ 216∘ 219∘ 237 222∘ 243∘ 252∘ 243∘ 264∘ 249∘ 255∘

Beam pointing error (deg) 0 minus12∘ 3∘ minus14∘ 22∘ minus14∘ minus34∘ minus34∘ minus16∘ minus41∘ minus59∘ 13∘

5 Conclusion

We propose a compact polarization tracking active phasedarray for Ku-band satellite communicationThe phased arraywith the height of 55mm is suited to be used in the applicationstrictly limiting the profile of the antenna Based on thesimulated single radiating element a small 7 times 7 array modelwas established with the simulation tool CST MicrowaveStudio The outermost 24 elements are connected to 50Ωpassive loads which contributes to the 5 times 5 active array Thewhole array was simulated and the effects of mutual couplingon the impedance of the ports can be analyzed Based onthe dimensional parameters of the isolated antenna elementthe parameters were adjusted via numerous simulations Thefinal design with mutual coupling considered had loweractive reflection coefficient of minus15 dB with beam pointed tothe boresight of the array When the array operates in thestates of horizontal vertical and diagonal polarization thesimulated active reflection coefficients versus the scan anglefor central element are plotted Furthermore we propose a

compact LTCC-based polarization trackingmodule based ona vertical transition from planar waveguide to stripline Inthe frequency range from 1225GHz to 1275GHz a smallpolarization tracking active phased array prototypewas fabri-cated and its polarization can be configured electronically viathe proposed modules The measured polarization trackingpatterns for horizontal vertical and diagonal polarization aregiven It can be found from the measurement that the beamcan be steered up to 50∘ in the elevation and the peak gain ismore than 160 dBiThe aperture efficiency of more than 50can be obtained The experiment validates the availability ofthe array design with mutual coupling considered

References

[1] S Yamamoto S Nuimura T Mizuno and Y Inasawa ldquoA Kuband small reflector antenna using backfire primary radiator forsatellite communication system on board vesselrdquo in Proceedingsof the International Symposium on Antennas and Propagation(ISAP rsquo12) pp 1273ndash1276 Nagoya Japan October 2012

12 International Journal of Antennas and Propagation

[2] J Thornton A White and G Long ldquoMulti-beam scanninglens antenna for satellite communications to trainsrdquoMicrowaveJournal vol 52 no 8 pp 56ndash70 2009

[3] A RWeily andNNikolic ldquoDual-polarized planar feed for low-profile hemispherical Luneburg lens antennasrdquo IEEE Transac-tions on Antennas and Propagation vol 60 no 1 pp 402ndash4072012

[4] S H Son and U H Park ldquoSidelobe reduction of low-profilearray antenna using a genetic algorithmrdquo ETRI Journal vol 29no 1 pp 95ndash98 2007

[5] PMousaviM Fakharzadeh S H Jamali et al ldquoA low-cost ultralow profile phased array system for mobile satellite receptionusing zero-knowledge beamforming algorithmrdquo IEEE Transac-tions on Antennas and Propagation vol 56 no 12 pp 3667ndash3679 2008

[6] S Vaccaro F Tiezzi M F Rua and C D G De Oro ldquoKu-BandLow-Profile Rx-only and Tx-Rx antennas for mobile satellitecommunicationsrdquo in Proceedings of the 4th IEEE InternationalSymposium on Phased Array Systems and Technology (Array rsquo10)pp 536ndash542 Waltham Mass USA October 2010

[7] R V Gatti L Marcaccioli E Sbarra and R SorrentinoldquoFlat array antennas for Ku-band mobile satellite terminalsrdquoInternational Journal of Antennas and Propagation vol 2009Article ID 836074 5 pages 2009

[8] C O Adler A D Monk D N Rasmussen and M J TaylorldquoTwo-way airborne broadband communications using phasedarray antennasrdquo in Proceedings of the IEEE Aerospace Confer-ence vol 2 pp 925ndash922 March 2003

[9] S Hasegawa T Yasuzumi O Hashimoto and Y KazamaldquoPolarization tracking phased array antenna with cross dipoleantenna-measured resultsrdquo in Proceedings of the IEEE Inter-national Symposium on Antennas and Propagation TorontoCanada July 2010

[10] J Zhou W Shi W B Dou and Y Shen ldquoHigh integratedmicrowave architecture using LTCC-SIP technology in activephased array antenna applicationsrdquo Frequenz vol 66 pp 177ndash182 2012

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

RoboticsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Active and Passive Electronic Components

Control Scienceand Engineering

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

RotatingMachinery

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Submit your manuscripts athttpwwwhindawicom

VLSI Design

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Shock and Vibration

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Civil EngineeringAdvances in

Acoustics and VibrationAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Electrical and Computer Engineering

Journal of

Advances inOptoElectronics

Hindawi Publishing Corporation httpwwwhindawicom

Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

SensorsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chemical EngineeringInternational Journal of Antennas and

Propagation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Navigation and Observation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

DistributedSensor Networks

International Journal of

International Journal of Antennas and Propagation 3

R1 R2-2 R3-3 R4-4 R5-5

R2-1 R3-2 R4-3 R5-4 R4-4

R3-1 R4-2 R5-3 R4-3 R3-3

R4-1 R5-2 R4-2 R3-2 R2-2

R5-1 R4-1 R3-1 R2-1 R1

(a) Layout

y

xo

120593

(b) Coordinate system

Figure 2 Topology of the small array (the outermost elements with gray color indicate passive elements terminated with 50Ω matchedloads)

0

minus5

minus10

minus15

minus20

minus25

S11S12

|S11|

(dB)

0

minus5

minus10

minus15

minus20

minus30

minus25

minus35

|S12|

(dB)

100 110 120 130 140 150Frequency (dB)

Figure 3 The simulated 11987811

and 11987812

of isolated antenna element

to a large array for the center element R5-3 Thus the effectof mutual coupling on the impedance of radiating element aswell as active element pattern can be analyzedThe radiatingelements are spaced a distance of 05 120582

0 wherein 120582

0is the

wavelength in free space at 125 GHzThe outermost elementswith gray color are terminated with loads of 50Ω to formpassive elements which are used to solve the problem ofdeterioration of edge element pattern of the inner 5times5 activearray

We used software CST Microwave Studio to design theisolated radiating element Array A in Table 1 was formed by7 rows of 7 elements designed without considering mutualcoupling The structural symmetry of isolated element con-tributes to the same simulated reflection coefficients of dualports shown in Figure 3 The simulated 10 dB impedancebandwidth (|119878

11| lt minus10 dB) was found to be 16 (18 GHzsim

138 GHz) which is sufficient for Ku-band satellite receiversystem Furthermore the coupling coefficient between port

Table 1 The structural parameters for the radiating element (unitmm)

Element parameters 119882up 119882low 119908 119897 119871probe

Array A (initial design ) 75 78 14 105 04Array B (final design ) 66 79 085 105 04

H and port V is belowminus18 dBHowever the difficult challengewith the polarization tracking phased array is the mutualcoupling which will result in the variation of the portimpedance of each element during polarization tracking andbeam scanningThus the design parameters in Table 1 for theradiating element in array A may be not optimum due tothe presence of mutual coupling thereby degrading the arrayperformance

A small array model was established in CST MicrowaveStudio for mutual coupling analysis If the amplitude

4 International Journal of Antennas and Propagation

Port V

Port H

0 5 10 15 20 25 30 35 40 45 50Scan angle (deg)

minus5

minus10

minus15

minus20

minus25

minus30

Activ

e refl

ectio

n co

effici

ent (

dB)

1225 GHz125 GHz1275GHz

(a) Array A

Port V

Port H

0 5 10 15 20 25 30 35 40 45 50Scan angle (deg)

minus10

minus16

minus20

minus28

minus34

minus32

minus30

minus26

minus24

minus22

minus18

minus14

minus12

Activ

e refl

ectio

n co

effici

ent (

dB)

1225 GHz125 GHz1275GHz

(b) Array B

Figure 4 The active reflection coefficient of central element R5-3 (azimuth angle 120593 = 0∘ vertical polarization)

Port V

Port H

0 5 10 15 20 25 30 35 40 45 50Scan angle (deg)

minus5

minus10

minus15

minus20

minus25

minus30

Activ

e refl

ectio

n co

effici

ent (

dB)

1225 GHz125 GHz1275GHz

(a) Array A

Port V

Port H

0 5 10 15 20 25 30 35 40 45 50Scan angle (deg)

minus5

minus10

minus15

minus20

minus25

minus30

Activ

e refl

ectio

n co

effici

ent (

dB)

1225 GHz125 GHz1275GHz

(b) Array B

Figure 5 The active reflection coefficient of central element R5-3 (azimuth angle 120593 = 0∘ horizontal polarization)

weighted coefficients for the orthogonal ports (port Hand port V) are (1 0) (0 1) and (1 1) respectivelythe small array will radiate vertically horizontally anddiagonally polarized wave In each polarization the beamcan be steered from 0∘ to 50∘ in elevation with phase vari-ation between antenna elements The key dimensionalparameters 119882up 119882low and 119908 can be adjusted via simulationtomitigate themutual coupling effect on the variation of portimpedance during polarization tracking and beam scanningThe new parameters of radiating elements proposed for arrayB are given in Table 1 The variations of active reflection

coefficient of central element R5-3 in both array A and arrayB are given in Figures 4 5 and 6 Compared with array A theactive reflection coefficient of central element R5-3 in arrayB has been reduced generally when the polarization trackingbeam is steered in the119909119911-plane (120593 = 0∘) within the scan rangeofplusmn25∘ As the scan angle increases the performance of activereflection coefficient of array B degrades gradually whichis obvious especially for the diagonal polarization Whenthe beam is steered to 50∘ in elevation the active reflectioncoefficient of about minus7 dB in the frequency range can beachieved for port HThe gain versus scan angle of both array

International Journal of Antennas and Propagation 5

minus5

minus6

minus7

minus8

minus9

minus10

minus11

minus12

minus13

minus14

minus15

minus16

minus17

minus18

Activ

e refl

ectio

n co

effici

ent (

dB)

0 5 10 15 20 25 30 35 40 45 50Scan angle (deg)

1225 GHz125 GHz1275GHz

Port V

Port H

(a) Array A

minus6

minus8

minus10

minus12

minus14

minus16

minus18

Activ

e refl

ectio

n co

effici

ent (

dB)

0 5 10 15 20 25 30 35 40 45 50Scan angle (deg)

1225 GHz125 GHz1275GHz

Port V

Port H

(b) Array B

Figure 6 The active reflection coefficient of central element R5-3 (azimuth angle 120593 = 0∘ diagonal polarization)

A and array B was computed for comparison The simulatedresults for three typical polarizations are shown in Figure 7The gain improvement for array B can be observed

As shown in Figure 8 a small 7 times 7 element array wasfabricated based on the dimensional parameters of array BThe active element patterns of central element R5-3 weremeasured when all of the other ports except for port V wereterminated with passive loads of 50Ω With reference toFigure 2 the 119909119911-plane (120593 = 0∘) is the H-plane for port V andthe 119910119911-plane (120593 = 90∘) is the E-planeThe active element pat-terns of central element R5-3 in H- and E-planes are given inFigure 9 In the area of the main lobe the agreement betweenthe simulated and measured results can be observed Boththe simulated and measured results indicate the half-powerbeamwidth of approximately 120∘ and 112∘ in the H-planeand the E-plane respectively No blind spot is observed Dueto the approximate symmetry in structure the active elementpattern of port H has the similarity with that of port V

3 Polarization Tracking Module

The polarization tracking modules are key components forthe polarization tracking active phased array The dualinput ports shown in Figure 10(b) are connected to theorthogonal dual ports of antenna element The dual inputsfrom port V and port H can be combined into singleoutput in phase via differential phase setting Δ120593 Thus thepolarization mismatch with incoming wave from satellitecan be avoided Figure 10(a) shows the coordinate sys-tem based on the unit vectors of orthogonal polarizationswherein 997888V and

997888

ℎ denote the vertical and horizontal polar-izations respectively The orientation of polarization for theincoming wave is denoted by 997888119901 and the included angleformed by 997888119901 and 997888V is denoted by 997888120572 If we neglect the

effects of radiation patterns of dual ports the inputs of theLange coupler are obtained as follows

PortC

1199063= 119886radic119866amp cos120572 (1a)

PortD

1199064= 119886radic119866amp sin120572 (1b)

wherein 119866amp is the gain of the LNA Assuming that the twochannels are consistent the signal at the output of the receivermodule can be yielded as

119906119888=

119886

2radic119871119879

radic119866amp exp [119895 (180∘

minus 120572 + 1205930)]

+

119886

2radic119871119879

radic119866amp exp [119895 (90∘

+ 1205930+ Δ120593 + 120572)]

(2)

Herein 119871119879is the average insertion loss in each channel

If the phase factor in (2) satisfies the condition as follows

Δ120593 = 90∘

minus 2120572 (3)

the combined signal has no polarization mismatch loss Inthis case the maximum combined signal is given as

119906119888=

119886

radic119871119879

radic119866amp exp [119895 (180∘

minus 120572 + 1205930)] (4)

Based on LTCC technology a vertical transition fromcoplanar waveguide to stripline is presented to reduce thesize of the module [10] Figure 11 shows the vertical transitionconfiguration and fabricated prototype The simulated and

6 International Journal of Antennas and Propagation

190

185

180

175

170

165

Gai

n (d

Bi)

minus10 0 10 20 30 40 50 60Scan angle (deg)

Array B (final design)Array A (initial design)

(a) Horizontal polarization

190

185

180

175

170

Gai

n (d

Bi)

minus10 0 10 20 30 40 50 60Scan angle (deg)

Array B (final design)Array A (initial design)

(b) Vertical polarization

190

185

180

175

170

Gai

n (d

Bi)

minus10 0 10 20 30 40 50 60Scan angle (deg)

Array B (final design)Array A (initial design)

(c) Diagonal polarization

Figure 7 The comparison of gain during polarization tracking and beam scanning (azimuth angle 120593 = 0∘)

Figure 8 Front view of the fabricated array

International Journal of Antennas and Propagation 7

50

minus5

minus10

minus15

minus20

minus25

minus30

minus35

minus40

minus45

minus50

minus55

minus60

Relat

ive a

mpl

itude

(dB)

MeasuredSimulated

minus180 minus120 minus60 0 60 120 180Angle (deg)

(a) 120593 = 0∘ (H-plane)

50

minus5

minus10

minus15

minus20

minus25

minus30

minus35

minus40

minus45

minus50

Relat

ive a

mpl

itude

(dB)

MeasuredSimulated

minus180 minus120 minus60 0 60 120 180Angle (deg)

(b) 120593 = 90∘ (E-plane)

Figure 9 The active element pattern of central element R5-3 fed from port V

120572

p

h

(a) Polarization decomposition

Receiving element

Port VPort H

LNA 2LNA 1

Lange coupler

1205930 1205930 + Δ120593

Power combiner

1 2

3 4

(b) Schematic block diagram

Figure 10 The polarization tracking module for receiving application

Ground

Coplanar waveguide

Metalized via LTCC

OutputInput

Motherboard

Stripline

(a) Schematic diagram (b) Prototype

Figure 11 Transition from planar waveguide to stripline based on LTCC technology

8 International Journal of Antennas and Propagation

0

minus15

minus30

minus45

minus60

|S11|

(dB)

0 2 4 6 8 10 12 14 16 18Frequency (GHz)

00

minus25

minus50

minus75

minus100

Inse

rtio

n lo

ss (d

B)

MeasuredSimulated

Figure 12 Reflection coefficient and insertion loss of the LTCC-based vertical transition

(a) Top view (b) Bottom view

Figure 13 The fabricated compact polarization tracking module

measured reflection coefficient and insertion loss are plottedin Figure 12 It is observed that good agreement can beobtained between the simulated and measured results from2GHz to 18GHzThemeasured reflection coefficient is belowminus16 dB and the insertion loss is less than 15 dB We usedthe compact structure of the vertical transition to developa polarization tracking module integrated with multipleMMICs which is shown in Figure 13 With reference toFigure 10(b) the gain of two channels of the module wasmeasured with 120593

0= 0∘ when Δ120593 was increased from 0∘ to

minus360∘ with a step of minus5625∘ With reference to Figure 14the measured gain of both channels varies in the range fromabout 10 dB to 35 dBwith different trend which is determinedby the differential phase Δ120593 between two channels Thusthe different amplitude weighted coefficients for both port Vand port H can be achieved which results in the arbitrarylinear polarization of the antenna element With referenceto Figure 14 the diagonal polarization (120572 = 45∘ and 120572 =minus45∘) can be obtained due to the approximately same gain

of both channels with Δ120593 = 0∘ and minus180∘ The approximatevertical polarization can be obtained with Δ120593 = minus90∘ whenthe measured gains of port H and port V are about 105 dBand 337 dB The approximate horizontal polarization can beobtained with Δ120593 = minus270∘ when the measured gains of portH and port V are about 342 dB and 105 dB

4 Experiment Result

A small 7 times 7 polarization tracking active phased arraywas fabricated to cover the frequency range from 1225GHzto 1275GHz The inner 5 times 5 radiating elements are con-nected to the polarization tracking modules discussed aboveThe miniature 50Ω SMP female terminations are used asmatched loads directly connecting to the outermost 24passive radiating elements The schematic block diagram ofthe fabricated array is shown in Figure 15 The compact-ness of the polarization tracking module based on LTCC-SiP technology contributes to the low-profile phased arraywith the size of 120mm (length)times 120mm (width) times 55mm(height) The polarization tracking patterns were measuredin 119909119911-planeThe antenna prototype to be measured was fixedon the rotary platform in the microwave chamber and thepolarization can be controlled electronically without rotatingthe array aperture The patterns for horizontal vertical anddiagonal polarization can be measured respectively withΔ120593 = minus270

∘

minus90∘ and 0∘ The narrow bandwidth of

4 determines the stable radiation patterns over the entireoperating frequency range from 1225GHz to 1275GHzThus the polarization tracking patternsmeasured at 125GHzwith beam scanned to 0∘ 20∘ 40∘ and 50∘ are given inFigures 16 17 18 and 19 The reasonable agreement between

International Journal of Antennas and Propagation 9

40

35

30

25

20

15

10

5

Differential phase (deg)

Gai

n (d

B)

Port HPort V

0 minus45 minus90 minus135 minus180 minus225 minus270 minus315 minus360

Figure 14 The measured transmission gain versus the differential phase Δ120593 for port H and port V

Polarizationtrackingmodule

Polarizationtrackingmodule

Polarizationtrackingmodule

Polarizationtrackingmodule

Polarizationtrackingmodule

Power combiner network

Beam and polarizationcontroller

Antenna array

middot middot middot

middot middot middot

middot middot middot

Figure 15 The schematic block diagram of the fabricated polarization tracking active phased array

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB) 20 20

(a) Horizontal polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB) 20 20

(b) Vertical polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

MeasuredSimulated

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB) 20 20

(c) Diagonal polarization

Figure 16 The polarization tracking patterns measured at 125 GHz with beam scanned to 0∘

10 International Journal of Antennas and Propagation

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

(a) Horizontal polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB) 3

(b) Vertical polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

MeasuredSimulated

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

(c) Diagonal polarization

Figure 17 The polarization tracking patterns measured at 125 GHz with beam scanned to 20∘

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

0

0

minus60

minus50minus40

minus3020

3040

5060

7

8

(a) Horizontal polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

4

(b) Vertical polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

MeasuredSimulated

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

40

(c) Diagonal polarization

Figure 18 The polarization tracking patterns measured at 125 GHz with beam scanned to 40∘

the simulated and measured results can be observed Thesummary of the antenna prototype performance measured at125 GHz is provided in Table 2 wherein H V and D denotehorizontal vertical and diagonal polarization It is found thatthe mutual coupling results in the sidelobe level are greaterthan minus10 dB when the beam is steered to the angle greaterthan 40∘ Furthermore the beamwidth and beam pointingerror increase Table 2 gives the measured peak gain of the

polarization tracking array prototype during beam scanningand polarization tracking Compared with the simulatedresults small errors exist Since there are actually 5 times 5 activeradiating elements in the small 7 times 7 array the maximumdirectivity of the array is approximately 189 dBi Thus theaperture efficiency greater than 50 for the polarizationtracking array prototype can be evaluated according to themeasured peak gain

International Journal of Antennas and Propagation 11

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

50

(a) Horizontal polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

5

(b) Vertical polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

MeasuredSimulated

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

50

(c) Diagonal polarization

Figure 19 The polarization tracking patterns measured at 125 GHz with beam scanned to 50∘

Table 2 The measured data at 125 GHz for the developed small phased array prototype

Desired scan angle (deg) 0∘ 20∘ 40∘ 50∘

H V D H V D H V D H V DPeak gain (dBi)

Simulated 187 187 187 184 185 185 177 179 179 169 175 173Measured 183 185 182 179 177 180 172 174 175 161 163 162

Aperture efficiency () 87 91 85 79 76 81 68 71 72 52 55 53SLL (dB) minus133 minus118 minus113 minus123 minus133 minus106 minus113 minus84 minus60 minus79 minus88 minus74Half-power beam width (deg) 222∘ 213∘ 216∘ 219∘ 237 222∘ 243∘ 252∘ 243∘ 264∘ 249∘ 255∘

Beam pointing error (deg) 0 minus12∘ 3∘ minus14∘ 22∘ minus14∘ minus34∘ minus34∘ minus16∘ minus41∘ minus59∘ 13∘

5 Conclusion

We propose a compact polarization tracking active phasedarray for Ku-band satellite communicationThe phased arraywith the height of 55mm is suited to be used in the applicationstrictly limiting the profile of the antenna Based on thesimulated single radiating element a small 7 times 7 array modelwas established with the simulation tool CST MicrowaveStudio The outermost 24 elements are connected to 50Ωpassive loads which contributes to the 5 times 5 active array Thewhole array was simulated and the effects of mutual couplingon the impedance of the ports can be analyzed Based onthe dimensional parameters of the isolated antenna elementthe parameters were adjusted via numerous simulations Thefinal design with mutual coupling considered had loweractive reflection coefficient of minus15 dB with beam pointed tothe boresight of the array When the array operates in thestates of horizontal vertical and diagonal polarization thesimulated active reflection coefficients versus the scan anglefor central element are plotted Furthermore we propose a

compact LTCC-based polarization trackingmodule based ona vertical transition from planar waveguide to stripline Inthe frequency range from 1225GHz to 1275GHz a smallpolarization tracking active phased array prototypewas fabri-cated and its polarization can be configured electronically viathe proposed modules The measured polarization trackingpatterns for horizontal vertical and diagonal polarization aregiven It can be found from the measurement that the beamcan be steered up to 50∘ in the elevation and the peak gain ismore than 160 dBiThe aperture efficiency of more than 50can be obtained The experiment validates the availability ofthe array design with mutual coupling considered

References

[1] S Yamamoto S Nuimura T Mizuno and Y Inasawa ldquoA Kuband small reflector antenna using backfire primary radiator forsatellite communication system on board vesselrdquo in Proceedingsof the International Symposium on Antennas and Propagation(ISAP rsquo12) pp 1273ndash1276 Nagoya Japan October 2012

12 International Journal of Antennas and Propagation

[2] J Thornton A White and G Long ldquoMulti-beam scanninglens antenna for satellite communications to trainsrdquoMicrowaveJournal vol 52 no 8 pp 56ndash70 2009

[3] A RWeily andNNikolic ldquoDual-polarized planar feed for low-profile hemispherical Luneburg lens antennasrdquo IEEE Transac-tions on Antennas and Propagation vol 60 no 1 pp 402ndash4072012

[4] S H Son and U H Park ldquoSidelobe reduction of low-profilearray antenna using a genetic algorithmrdquo ETRI Journal vol 29no 1 pp 95ndash98 2007

[5] PMousaviM Fakharzadeh S H Jamali et al ldquoA low-cost ultralow profile phased array system for mobile satellite receptionusing zero-knowledge beamforming algorithmrdquo IEEE Transac-tions on Antennas and Propagation vol 56 no 12 pp 3667ndash3679 2008

[6] S Vaccaro F Tiezzi M F Rua and C D G De Oro ldquoKu-BandLow-Profile Rx-only and Tx-Rx antennas for mobile satellitecommunicationsrdquo in Proceedings of the 4th IEEE InternationalSymposium on Phased Array Systems and Technology (Array rsquo10)pp 536ndash542 Waltham Mass USA October 2010

[7] R V Gatti L Marcaccioli E Sbarra and R SorrentinoldquoFlat array antennas for Ku-band mobile satellite terminalsrdquoInternational Journal of Antennas and Propagation vol 2009Article ID 836074 5 pages 2009

[8] C O Adler A D Monk D N Rasmussen and M J TaylorldquoTwo-way airborne broadband communications using phasedarray antennasrdquo in Proceedings of the IEEE Aerospace Confer-ence vol 2 pp 925ndash922 March 2003

[9] S Hasegawa T Yasuzumi O Hashimoto and Y KazamaldquoPolarization tracking phased array antenna with cross dipoleantenna-measured resultsrdquo in Proceedings of the IEEE Inter-national Symposium on Antennas and Propagation TorontoCanada July 2010

[10] J Zhou W Shi W B Dou and Y Shen ldquoHigh integratedmicrowave architecture using LTCC-SIP technology in activephased array antenna applicationsrdquo Frequenz vol 66 pp 177ndash182 2012

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

RoboticsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Active and Passive Electronic Components

Control Scienceand Engineering

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

RotatingMachinery

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Submit your manuscripts athttpwwwhindawicom

VLSI Design

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Shock and Vibration

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Civil EngineeringAdvances in

Acoustics and VibrationAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Electrical and Computer Engineering

Journal of

Advances inOptoElectronics

Hindawi Publishing Corporation httpwwwhindawicom

Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

SensorsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chemical EngineeringInternational Journal of Antennas and

Propagation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Navigation and Observation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

DistributedSensor Networks

International Journal of

4 International Journal of Antennas and Propagation

Port V

Port H

0 5 10 15 20 25 30 35 40 45 50Scan angle (deg)

minus5

minus10

minus15

minus20

minus25

minus30

Activ

e refl

ectio

n co

effici

ent (

dB)

1225 GHz125 GHz1275GHz

(a) Array A

Port V

Port H

0 5 10 15 20 25 30 35 40 45 50Scan angle (deg)

minus10

minus16

minus20

minus28

minus34

minus32

minus30

minus26

minus24

minus22

minus18

minus14

minus12

Activ

e refl

ectio

n co

effici

ent (

dB)

1225 GHz125 GHz1275GHz

(b) Array B

Figure 4 The active reflection coefficient of central element R5-3 (azimuth angle 120593 = 0∘ vertical polarization)

Port V

Port H

0 5 10 15 20 25 30 35 40 45 50Scan angle (deg)

minus5

minus10

minus15

minus20

minus25

minus30

Activ

e refl

ectio

n co

effici

ent (

dB)

1225 GHz125 GHz1275GHz

(a) Array A

Port V

Port H

0 5 10 15 20 25 30 35 40 45 50Scan angle (deg)

minus5

minus10

minus15

minus20

minus25

minus30

Activ

e refl

ectio

n co

effici

ent (

dB)

1225 GHz125 GHz1275GHz

(b) Array B

Figure 5 The active reflection coefficient of central element R5-3 (azimuth angle 120593 = 0∘ horizontal polarization)

weighted coefficients for the orthogonal ports (port Hand port V) are (1 0) (0 1) and (1 1) respectivelythe small array will radiate vertically horizontally anddiagonally polarized wave In each polarization the beamcan be steered from 0∘ to 50∘ in elevation with phase vari-ation between antenna elements The key dimensionalparameters 119882up 119882low and 119908 can be adjusted via simulationtomitigate themutual coupling effect on the variation of portimpedance during polarization tracking and beam scanningThe new parameters of radiating elements proposed for arrayB are given in Table 1 The variations of active reflection

coefficient of central element R5-3 in both array A and arrayB are given in Figures 4 5 and 6 Compared with array A theactive reflection coefficient of central element R5-3 in arrayB has been reduced generally when the polarization trackingbeam is steered in the119909119911-plane (120593 = 0∘) within the scan rangeofplusmn25∘ As the scan angle increases the performance of activereflection coefficient of array B degrades gradually whichis obvious especially for the diagonal polarization Whenthe beam is steered to 50∘ in elevation the active reflectioncoefficient of about minus7 dB in the frequency range can beachieved for port HThe gain versus scan angle of both array

International Journal of Antennas and Propagation 5

minus5

minus6

minus7

minus8

minus9

minus10

minus11

minus12

minus13

minus14

minus15

minus16

minus17

minus18

Activ

e refl

ectio

n co

effici

ent (

dB)

0 5 10 15 20 25 30 35 40 45 50Scan angle (deg)

1225 GHz125 GHz1275GHz

Port V

Port H

(a) Array A

minus6

minus8

minus10

minus12

minus14

minus16

minus18

Activ

e refl

ectio

n co

effici

ent (

dB)

0 5 10 15 20 25 30 35 40 45 50Scan angle (deg)

1225 GHz125 GHz1275GHz

Port V

Port H

(b) Array B

Figure 6 The active reflection coefficient of central element R5-3 (azimuth angle 120593 = 0∘ diagonal polarization)

A and array B was computed for comparison The simulatedresults for three typical polarizations are shown in Figure 7The gain improvement for array B can be observed

As shown in Figure 8 a small 7 times 7 element array wasfabricated based on the dimensional parameters of array BThe active element patterns of central element R5-3 weremeasured when all of the other ports except for port V wereterminated with passive loads of 50Ω With reference toFigure 2 the 119909119911-plane (120593 = 0∘) is the H-plane for port V andthe 119910119911-plane (120593 = 90∘) is the E-planeThe active element pat-terns of central element R5-3 in H- and E-planes are given inFigure 9 In the area of the main lobe the agreement betweenthe simulated and measured results can be observed Boththe simulated and measured results indicate the half-powerbeamwidth of approximately 120∘ and 112∘ in the H-planeand the E-plane respectively No blind spot is observed Dueto the approximate symmetry in structure the active elementpattern of port H has the similarity with that of port V

3 Polarization Tracking Module

The polarization tracking modules are key components forthe polarization tracking active phased array The dualinput ports shown in Figure 10(b) are connected to theorthogonal dual ports of antenna element The dual inputsfrom port V and port H can be combined into singleoutput in phase via differential phase setting Δ120593 Thus thepolarization mismatch with incoming wave from satellitecan be avoided Figure 10(a) shows the coordinate sys-tem based on the unit vectors of orthogonal polarizationswherein 997888V and

997888

ℎ denote the vertical and horizontal polar-izations respectively The orientation of polarization for theincoming wave is denoted by 997888119901 and the included angleformed by 997888119901 and 997888V is denoted by 997888120572 If we neglect the

effects of radiation patterns of dual ports the inputs of theLange coupler are obtained as follows

PortC

1199063= 119886radic119866amp cos120572 (1a)

PortD

1199064= 119886radic119866amp sin120572 (1b)

wherein 119866amp is the gain of the LNA Assuming that the twochannels are consistent the signal at the output of the receivermodule can be yielded as

119906119888=

119886

2radic119871119879

radic119866amp exp [119895 (180∘

minus 120572 + 1205930)]

+

119886

2radic119871119879

radic119866amp exp [119895 (90∘

+ 1205930+ Δ120593 + 120572)]

(2)

Herein 119871119879is the average insertion loss in each channel

If the phase factor in (2) satisfies the condition as follows

Δ120593 = 90∘

minus 2120572 (3)

the combined signal has no polarization mismatch loss Inthis case the maximum combined signal is given as

119906119888=

119886

radic119871119879

radic119866amp exp [119895 (180∘

minus 120572 + 1205930)] (4)

Based on LTCC technology a vertical transition fromcoplanar waveguide to stripline is presented to reduce thesize of the module [10] Figure 11 shows the vertical transitionconfiguration and fabricated prototype The simulated and

6 International Journal of Antennas and Propagation

190

185

180

175

170

165

Gai

n (d

Bi)

minus10 0 10 20 30 40 50 60Scan angle (deg)

Array B (final design)Array A (initial design)

(a) Horizontal polarization

190

185

180

175

170

Gai

n (d

Bi)

minus10 0 10 20 30 40 50 60Scan angle (deg)

Array B (final design)Array A (initial design)

(b) Vertical polarization

190

185

180

175

170

Gai

n (d

Bi)

minus10 0 10 20 30 40 50 60Scan angle (deg)

Array B (final design)Array A (initial design)

(c) Diagonal polarization

Figure 7 The comparison of gain during polarization tracking and beam scanning (azimuth angle 120593 = 0∘)

Figure 8 Front view of the fabricated array

International Journal of Antennas and Propagation 7

50

minus5

minus10

minus15

minus20

minus25

minus30

minus35

minus40

minus45

minus50

minus55

minus60

Relat

ive a

mpl

itude

(dB)

MeasuredSimulated

minus180 minus120 minus60 0 60 120 180Angle (deg)

(a) 120593 = 0∘ (H-plane)

50

minus5

minus10

minus15

minus20

minus25

minus30

minus35

minus40

minus45

minus50

Relat

ive a

mpl

itude

(dB)

MeasuredSimulated

minus180 minus120 minus60 0 60 120 180Angle (deg)

(b) 120593 = 90∘ (E-plane)

Figure 9 The active element pattern of central element R5-3 fed from port V

120572

p

h

(a) Polarization decomposition

Receiving element

Port VPort H

LNA 2LNA 1

Lange coupler

1205930 1205930 + Δ120593

Power combiner

1 2

3 4

(b) Schematic block diagram

Figure 10 The polarization tracking module for receiving application

Ground

Coplanar waveguide

Metalized via LTCC

OutputInput

Motherboard

Stripline

(a) Schematic diagram (b) Prototype

Figure 11 Transition from planar waveguide to stripline based on LTCC technology

8 International Journal of Antennas and Propagation

0

minus15

minus30

minus45

minus60

|S11|

(dB)

0 2 4 6 8 10 12 14 16 18Frequency (GHz)

00

minus25

minus50

minus75

minus100

Inse

rtio

n lo

ss (d

B)

MeasuredSimulated

Figure 12 Reflection coefficient and insertion loss of the LTCC-based vertical transition

(a) Top view (b) Bottom view

Figure 13 The fabricated compact polarization tracking module

measured reflection coefficient and insertion loss are plottedin Figure 12 It is observed that good agreement can beobtained between the simulated and measured results from2GHz to 18GHzThemeasured reflection coefficient is belowminus16 dB and the insertion loss is less than 15 dB We usedthe compact structure of the vertical transition to developa polarization tracking module integrated with multipleMMICs which is shown in Figure 13 With reference toFigure 10(b) the gain of two channels of the module wasmeasured with 120593

0= 0∘ when Δ120593 was increased from 0∘ to

minus360∘ with a step of minus5625∘ With reference to Figure 14the measured gain of both channels varies in the range fromabout 10 dB to 35 dBwith different trend which is determinedby the differential phase Δ120593 between two channels Thusthe different amplitude weighted coefficients for both port Vand port H can be achieved which results in the arbitrarylinear polarization of the antenna element With referenceto Figure 14 the diagonal polarization (120572 = 45∘ and 120572 =minus45∘) can be obtained due to the approximately same gain

of both channels with Δ120593 = 0∘ and minus180∘ The approximatevertical polarization can be obtained with Δ120593 = minus90∘ whenthe measured gains of port H and port V are about 105 dBand 337 dB The approximate horizontal polarization can beobtained with Δ120593 = minus270∘ when the measured gains of portH and port V are about 342 dB and 105 dB

4 Experiment Result

A small 7 times 7 polarization tracking active phased arraywas fabricated to cover the frequency range from 1225GHzto 1275GHz The inner 5 times 5 radiating elements are con-nected to the polarization tracking modules discussed aboveThe miniature 50Ω SMP female terminations are used asmatched loads directly connecting to the outermost 24passive radiating elements The schematic block diagram ofthe fabricated array is shown in Figure 15 The compact-ness of the polarization tracking module based on LTCC-SiP technology contributes to the low-profile phased arraywith the size of 120mm (length)times 120mm (width) times 55mm(height) The polarization tracking patterns were measuredin 119909119911-planeThe antenna prototype to be measured was fixedon the rotary platform in the microwave chamber and thepolarization can be controlled electronically without rotatingthe array aperture The patterns for horizontal vertical anddiagonal polarization can be measured respectively withΔ120593 = minus270

∘

minus90∘ and 0∘ The narrow bandwidth of

4 determines the stable radiation patterns over the entireoperating frequency range from 1225GHz to 1275GHzThus the polarization tracking patternsmeasured at 125GHzwith beam scanned to 0∘ 20∘ 40∘ and 50∘ are given inFigures 16 17 18 and 19 The reasonable agreement between

International Journal of Antennas and Propagation 9

40

35

30

25

20

15

10

5

Differential phase (deg)

Gai

n (d

B)

Port HPort V

0 minus45 minus90 minus135 minus180 minus225 minus270 minus315 minus360

Figure 14 The measured transmission gain versus the differential phase Δ120593 for port H and port V

Polarizationtrackingmodule

Polarizationtrackingmodule

Polarizationtrackingmodule

Polarizationtrackingmodule

Polarizationtrackingmodule

Power combiner network

Beam and polarizationcontroller

Antenna array

middot middot middot

middot middot middot

middot middot middot

Figure 15 The schematic block diagram of the fabricated polarization tracking active phased array

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB) 20 20

(a) Horizontal polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB) 20 20

(b) Vertical polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

MeasuredSimulated

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB) 20 20

(c) Diagonal polarization

Figure 16 The polarization tracking patterns measured at 125 GHz with beam scanned to 0∘

10 International Journal of Antennas and Propagation

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

(a) Horizontal polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB) 3

(b) Vertical polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

MeasuredSimulated

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

(c) Diagonal polarization

Figure 17 The polarization tracking patterns measured at 125 GHz with beam scanned to 20∘

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

0

0

minus60

minus50minus40

minus3020

3040

5060

7

8

(a) Horizontal polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

4

(b) Vertical polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

MeasuredSimulated

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

40

(c) Diagonal polarization

Figure 18 The polarization tracking patterns measured at 125 GHz with beam scanned to 40∘

the simulated and measured results can be observed Thesummary of the antenna prototype performance measured at125 GHz is provided in Table 2 wherein H V and D denotehorizontal vertical and diagonal polarization It is found thatthe mutual coupling results in the sidelobe level are greaterthan minus10 dB when the beam is steered to the angle greaterthan 40∘ Furthermore the beamwidth and beam pointingerror increase Table 2 gives the measured peak gain of the

polarization tracking array prototype during beam scanningand polarization tracking Compared with the simulatedresults small errors exist Since there are actually 5 times 5 activeradiating elements in the small 7 times 7 array the maximumdirectivity of the array is approximately 189 dBi Thus theaperture efficiency greater than 50 for the polarizationtracking array prototype can be evaluated according to themeasured peak gain

International Journal of Antennas and Propagation 11

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

50

(a) Horizontal polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

5

(b) Vertical polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

MeasuredSimulated

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

50

(c) Diagonal polarization

Figure 19 The polarization tracking patterns measured at 125 GHz with beam scanned to 50∘

Table 2 The measured data at 125 GHz for the developed small phased array prototype

Desired scan angle (deg) 0∘ 20∘ 40∘ 50∘

H V D H V D H V D H V DPeak gain (dBi)

Simulated 187 187 187 184 185 185 177 179 179 169 175 173Measured 183 185 182 179 177 180 172 174 175 161 163 162

Aperture efficiency () 87 91 85 79 76 81 68 71 72 52 55 53SLL (dB) minus133 minus118 minus113 minus123 minus133 minus106 minus113 minus84 minus60 minus79 minus88 minus74Half-power beam width (deg) 222∘ 213∘ 216∘ 219∘ 237 222∘ 243∘ 252∘ 243∘ 264∘ 249∘ 255∘

Beam pointing error (deg) 0 minus12∘ 3∘ minus14∘ 22∘ minus14∘ minus34∘ minus34∘ minus16∘ minus41∘ minus59∘ 13∘

5 Conclusion

We propose a compact polarization tracking active phasedarray for Ku-band satellite communicationThe phased arraywith the height of 55mm is suited to be used in the applicationstrictly limiting the profile of the antenna Based on thesimulated single radiating element a small 7 times 7 array modelwas established with the simulation tool CST MicrowaveStudio The outermost 24 elements are connected to 50Ωpassive loads which contributes to the 5 times 5 active array Thewhole array was simulated and the effects of mutual couplingon the impedance of the ports can be analyzed Based onthe dimensional parameters of the isolated antenna elementthe parameters were adjusted via numerous simulations Thefinal design with mutual coupling considered had loweractive reflection coefficient of minus15 dB with beam pointed tothe boresight of the array When the array operates in thestates of horizontal vertical and diagonal polarization thesimulated active reflection coefficients versus the scan anglefor central element are plotted Furthermore we propose a

compact LTCC-based polarization trackingmodule based ona vertical transition from planar waveguide to stripline Inthe frequency range from 1225GHz to 1275GHz a smallpolarization tracking active phased array prototypewas fabri-cated and its polarization can be configured electronically viathe proposed modules The measured polarization trackingpatterns for horizontal vertical and diagonal polarization aregiven It can be found from the measurement that the beamcan be steered up to 50∘ in the elevation and the peak gain ismore than 160 dBiThe aperture efficiency of more than 50can be obtained The experiment validates the availability ofthe array design with mutual coupling considered

References

[1] S Yamamoto S Nuimura T Mizuno and Y Inasawa ldquoA Kuband small reflector antenna using backfire primary radiator forsatellite communication system on board vesselrdquo in Proceedingsof the International Symposium on Antennas and Propagation(ISAP rsquo12) pp 1273ndash1276 Nagoya Japan October 2012

12 International Journal of Antennas and Propagation

[2] J Thornton A White and G Long ldquoMulti-beam scanninglens antenna for satellite communications to trainsrdquoMicrowaveJournal vol 52 no 8 pp 56ndash70 2009

[3] A RWeily andNNikolic ldquoDual-polarized planar feed for low-profile hemispherical Luneburg lens antennasrdquo IEEE Transac-tions on Antennas and Propagation vol 60 no 1 pp 402ndash4072012

[4] S H Son and U H Park ldquoSidelobe reduction of low-profilearray antenna using a genetic algorithmrdquo ETRI Journal vol 29no 1 pp 95ndash98 2007

[5] PMousaviM Fakharzadeh S H Jamali et al ldquoA low-cost ultralow profile phased array system for mobile satellite receptionusing zero-knowledge beamforming algorithmrdquo IEEE Transac-tions on Antennas and Propagation vol 56 no 12 pp 3667ndash3679 2008

[6] S Vaccaro F Tiezzi M F Rua and C D G De Oro ldquoKu-BandLow-Profile Rx-only and Tx-Rx antennas for mobile satellitecommunicationsrdquo in Proceedings of the 4th IEEE InternationalSymposium on Phased Array Systems and Technology (Array rsquo10)pp 536ndash542 Waltham Mass USA October 2010

[7] R V Gatti L Marcaccioli E Sbarra and R SorrentinoldquoFlat array antennas for Ku-band mobile satellite terminalsrdquoInternational Journal of Antennas and Propagation vol 2009Article ID 836074 5 pages 2009

[8] C O Adler A D Monk D N Rasmussen and M J TaylorldquoTwo-way airborne broadband communications using phasedarray antennasrdquo in Proceedings of the IEEE Aerospace Confer-ence vol 2 pp 925ndash922 March 2003

[9] S Hasegawa T Yasuzumi O Hashimoto and Y KazamaldquoPolarization tracking phased array antenna with cross dipoleantenna-measured resultsrdquo in Proceedings of the IEEE Inter-national Symposium on Antennas and Propagation TorontoCanada July 2010

[10] J Zhou W Shi W B Dou and Y Shen ldquoHigh integratedmicrowave architecture using LTCC-SIP technology in activephased array antenna applicationsrdquo Frequenz vol 66 pp 177ndash182 2012

International Journal of

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Journal ofEngineeringVolume 2014

Submit your manuscripts athttpwwwhindawicom

VLSI Design

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Shock and Vibration

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Civil EngineeringAdvances in

Acoustics and VibrationAdvances in

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Electrical and Computer Engineering

Journal of

Advances inOptoElectronics

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Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

SensorsJournal of

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Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014

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Chemical EngineeringInternational Journal of Antennas and

Propagation

International Journal of

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Navigation and Observation

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DistributedSensor Networks

International Journal of

International Journal of Antennas and Propagation 5

minus5

minus6

minus7

minus8

minus9

minus10

minus11

minus12

minus13

minus14

minus15

minus16

minus17

minus18

Activ

e refl

ectio

n co

effici

ent (

dB)

0 5 10 15 20 25 30 35 40 45 50Scan angle (deg)

1225 GHz125 GHz1275GHz

Port V

Port H

(a) Array A

minus6

minus8

minus10

minus12

minus14

minus16

minus18

Activ

e refl

ectio

n co

effici

ent (

dB)

0 5 10 15 20 25 30 35 40 45 50Scan angle (deg)

1225 GHz125 GHz1275GHz

Port V

Port H

(b) Array B

Figure 6 The active reflection coefficient of central element R5-3 (azimuth angle 120593 = 0∘ diagonal polarization)

A and array B was computed for comparison The simulatedresults for three typical polarizations are shown in Figure 7The gain improvement for array B can be observed

As shown in Figure 8 a small 7 times 7 element array wasfabricated based on the dimensional parameters of array BThe active element patterns of central element R5-3 weremeasured when all of the other ports except for port V wereterminated with passive loads of 50Ω With reference toFigure 2 the 119909119911-plane (120593 = 0∘) is the H-plane for port V andthe 119910119911-plane (120593 = 90∘) is the E-planeThe active element pat-terns of central element R5-3 in H- and E-planes are given inFigure 9 In the area of the main lobe the agreement betweenthe simulated and measured results can be observed Boththe simulated and measured results indicate the half-powerbeamwidth of approximately 120∘ and 112∘ in the H-planeand the E-plane respectively No blind spot is observed Dueto the approximate symmetry in structure the active elementpattern of port H has the similarity with that of port V

3 Polarization Tracking Module

The polarization tracking modules are key components forthe polarization tracking active phased array The dualinput ports shown in Figure 10(b) are connected to theorthogonal dual ports of antenna element The dual inputsfrom port V and port H can be combined into singleoutput in phase via differential phase setting Δ120593 Thus thepolarization mismatch with incoming wave from satellitecan be avoided Figure 10(a) shows the coordinate sys-tem based on the unit vectors of orthogonal polarizationswherein 997888V and

997888

ℎ denote the vertical and horizontal polar-izations respectively The orientation of polarization for theincoming wave is denoted by 997888119901 and the included angleformed by 997888119901 and 997888V is denoted by 997888120572 If we neglect the

effects of radiation patterns of dual ports the inputs of theLange coupler are obtained as follows

PortC

1199063= 119886radic119866amp cos120572 (1a)

PortD

1199064= 119886radic119866amp sin120572 (1b)

wherein 119866amp is the gain of the LNA Assuming that the twochannels are consistent the signal at the output of the receivermodule can be yielded as

119906119888=

119886

2radic119871119879

radic119866amp exp [119895 (180∘

minus 120572 + 1205930)]

+

119886

2radic119871119879

radic119866amp exp [119895 (90∘

+ 1205930+ Δ120593 + 120572)]

(2)

Herein 119871119879is the average insertion loss in each channel

If the phase factor in (2) satisfies the condition as follows

Δ120593 = 90∘

minus 2120572 (3)

the combined signal has no polarization mismatch loss Inthis case the maximum combined signal is given as

119906119888=

119886

radic119871119879

radic119866amp exp [119895 (180∘

minus 120572 + 1205930)] (4)

Based on LTCC technology a vertical transition fromcoplanar waveguide to stripline is presented to reduce thesize of the module [10] Figure 11 shows the vertical transitionconfiguration and fabricated prototype The simulated and

6 International Journal of Antennas and Propagation

190

185

180

175

170

165

Gai

n (d

Bi)

minus10 0 10 20 30 40 50 60Scan angle (deg)

Array B (final design)Array A (initial design)

(a) Horizontal polarization

190

185

180

175

170

Gai

n (d

Bi)

minus10 0 10 20 30 40 50 60Scan angle (deg)

Array B (final design)Array A (initial design)

(b) Vertical polarization

190

185

180

175

170

Gai

n (d

Bi)

minus10 0 10 20 30 40 50 60Scan angle (deg)

Array B (final design)Array A (initial design)

(c) Diagonal polarization

Figure 7 The comparison of gain during polarization tracking and beam scanning (azimuth angle 120593 = 0∘)

Figure 8 Front view of the fabricated array

International Journal of Antennas and Propagation 7

50

minus5

minus10

minus15

minus20

minus25

minus30

minus35

minus40

minus45

minus50

minus55

minus60

Relat

ive a

mpl

itude

(dB)

MeasuredSimulated

minus180 minus120 minus60 0 60 120 180Angle (deg)

(a) 120593 = 0∘ (H-plane)

50

minus5

minus10

minus15

minus20

minus25

minus30

minus35

minus40

minus45

minus50

Relat

ive a

mpl

itude

(dB)

MeasuredSimulated

minus180 minus120 minus60 0 60 120 180Angle (deg)

(b) 120593 = 90∘ (E-plane)

Figure 9 The active element pattern of central element R5-3 fed from port V

120572

p

h

(a) Polarization decomposition

Receiving element

Port VPort H

LNA 2LNA 1

Lange coupler

1205930 1205930 + Δ120593

Power combiner

1 2

3 4

(b) Schematic block diagram

Figure 10 The polarization tracking module for receiving application

Ground

Coplanar waveguide

Metalized via LTCC

OutputInput

Motherboard

Stripline

(a) Schematic diagram (b) Prototype

Figure 11 Transition from planar waveguide to stripline based on LTCC technology

8 International Journal of Antennas and Propagation

0

minus15

minus30

minus45

minus60

|S11|

(dB)

0 2 4 6 8 10 12 14 16 18Frequency (GHz)

00

minus25

minus50

minus75

minus100

Inse

rtio

n lo

ss (d

B)

MeasuredSimulated

Figure 12 Reflection coefficient and insertion loss of the LTCC-based vertical transition

(a) Top view (b) Bottom view

Figure 13 The fabricated compact polarization tracking module

measured reflection coefficient and insertion loss are plottedin Figure 12 It is observed that good agreement can beobtained between the simulated and measured results from2GHz to 18GHzThemeasured reflection coefficient is belowminus16 dB and the insertion loss is less than 15 dB We usedthe compact structure of the vertical transition to developa polarization tracking module integrated with multipleMMICs which is shown in Figure 13 With reference toFigure 10(b) the gain of two channels of the module wasmeasured with 120593

0= 0∘ when Δ120593 was increased from 0∘ to

minus360∘ with a step of minus5625∘ With reference to Figure 14the measured gain of both channels varies in the range fromabout 10 dB to 35 dBwith different trend which is determinedby the differential phase Δ120593 between two channels Thusthe different amplitude weighted coefficients for both port Vand port H can be achieved which results in the arbitrarylinear polarization of the antenna element With referenceto Figure 14 the diagonal polarization (120572 = 45∘ and 120572 =minus45∘) can be obtained due to the approximately same gain

of both channels with Δ120593 = 0∘ and minus180∘ The approximatevertical polarization can be obtained with Δ120593 = minus90∘ whenthe measured gains of port H and port V are about 105 dBand 337 dB The approximate horizontal polarization can beobtained with Δ120593 = minus270∘ when the measured gains of portH and port V are about 342 dB and 105 dB

4 Experiment Result

A small 7 times 7 polarization tracking active phased arraywas fabricated to cover the frequency range from 1225GHzto 1275GHz The inner 5 times 5 radiating elements are con-nected to the polarization tracking modules discussed aboveThe miniature 50Ω SMP female terminations are used asmatched loads directly connecting to the outermost 24passive radiating elements The schematic block diagram ofthe fabricated array is shown in Figure 15 The compact-ness of the polarization tracking module based on LTCC-SiP technology contributes to the low-profile phased arraywith the size of 120mm (length)times 120mm (width) times 55mm(height) The polarization tracking patterns were measuredin 119909119911-planeThe antenna prototype to be measured was fixedon the rotary platform in the microwave chamber and thepolarization can be controlled electronically without rotatingthe array aperture The patterns for horizontal vertical anddiagonal polarization can be measured respectively withΔ120593 = minus270

∘

minus90∘ and 0∘ The narrow bandwidth of

4 determines the stable radiation patterns over the entireoperating frequency range from 1225GHz to 1275GHzThus the polarization tracking patternsmeasured at 125GHzwith beam scanned to 0∘ 20∘ 40∘ and 50∘ are given inFigures 16 17 18 and 19 The reasonable agreement between

International Journal of Antennas and Propagation 9

40

35

30

25

20

15

10

5

Differential phase (deg)

Gai

n (d

B)

Port HPort V

0 minus45 minus90 minus135 minus180 minus225 minus270 minus315 minus360

Figure 14 The measured transmission gain versus the differential phase Δ120593 for port H and port V

Polarizationtrackingmodule

Polarizationtrackingmodule

Polarizationtrackingmodule

Polarizationtrackingmodule

Polarizationtrackingmodule

Power combiner network

Beam and polarizationcontroller

Antenna array

middot middot middot

middot middot middot

middot middot middot

Figure 15 The schematic block diagram of the fabricated polarization tracking active phased array

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB) 20 20

(a) Horizontal polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB) 20 20

(b) Vertical polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

MeasuredSimulated

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB) 20 20

(c) Diagonal polarization

Figure 16 The polarization tracking patterns measured at 125 GHz with beam scanned to 0∘

10 International Journal of Antennas and Propagation

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

(a) Horizontal polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB) 3

(b) Vertical polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

MeasuredSimulated

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

(c) Diagonal polarization

Figure 17 The polarization tracking patterns measured at 125 GHz with beam scanned to 20∘

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

0

0

minus60

minus50minus40

minus3020

3040

5060

7

8

(a) Horizontal polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

4

(b) Vertical polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

MeasuredSimulated

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

40

(c) Diagonal polarization

Figure 18 The polarization tracking patterns measured at 125 GHz with beam scanned to 40∘

the simulated and measured results can be observed Thesummary of the antenna prototype performance measured at125 GHz is provided in Table 2 wherein H V and D denotehorizontal vertical and diagonal polarization It is found thatthe mutual coupling results in the sidelobe level are greaterthan minus10 dB when the beam is steered to the angle greaterthan 40∘ Furthermore the beamwidth and beam pointingerror increase Table 2 gives the measured peak gain of the

polarization tracking array prototype during beam scanningand polarization tracking Compared with the simulatedresults small errors exist Since there are actually 5 times 5 activeradiating elements in the small 7 times 7 array the maximumdirectivity of the array is approximately 189 dBi Thus theaperture efficiency greater than 50 for the polarizationtracking array prototype can be evaluated according to themeasured peak gain

International Journal of Antennas and Propagation 11

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

50

(a) Horizontal polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

5

(b) Vertical polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

MeasuredSimulated

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

50

(c) Diagonal polarization

Figure 19 The polarization tracking patterns measured at 125 GHz with beam scanned to 50∘

Table 2 The measured data at 125 GHz for the developed small phased array prototype

Desired scan angle (deg) 0∘ 20∘ 40∘ 50∘

H V D H V D H V D H V DPeak gain (dBi)

Simulated 187 187 187 184 185 185 177 179 179 169 175 173Measured 183 185 182 179 177 180 172 174 175 161 163 162

Aperture efficiency () 87 91 85 79 76 81 68 71 72 52 55 53SLL (dB) minus133 minus118 minus113 minus123 minus133 minus106 minus113 minus84 minus60 minus79 minus88 minus74Half-power beam width (deg) 222∘ 213∘ 216∘ 219∘ 237 222∘ 243∘ 252∘ 243∘ 264∘ 249∘ 255∘

Beam pointing error (deg) 0 minus12∘ 3∘ minus14∘ 22∘ minus14∘ minus34∘ minus34∘ minus16∘ minus41∘ minus59∘ 13∘

5 Conclusion

We propose a compact polarization tracking active phasedarray for Ku-band satellite communicationThe phased arraywith the height of 55mm is suited to be used in the applicationstrictly limiting the profile of the antenna Based on thesimulated single radiating element a small 7 times 7 array modelwas established with the simulation tool CST MicrowaveStudio The outermost 24 elements are connected to 50Ωpassive loads which contributes to the 5 times 5 active array Thewhole array was simulated and the effects of mutual couplingon the impedance of the ports can be analyzed Based onthe dimensional parameters of the isolated antenna elementthe parameters were adjusted via numerous simulations Thefinal design with mutual coupling considered had loweractive reflection coefficient of minus15 dB with beam pointed tothe boresight of the array When the array operates in thestates of horizontal vertical and diagonal polarization thesimulated active reflection coefficients versus the scan anglefor central element are plotted Furthermore we propose a

compact LTCC-based polarization trackingmodule based ona vertical transition from planar waveguide to stripline Inthe frequency range from 1225GHz to 1275GHz a smallpolarization tracking active phased array prototypewas fabri-cated and its polarization can be configured electronically viathe proposed modules The measured polarization trackingpatterns for horizontal vertical and diagonal polarization aregiven It can be found from the measurement that the beamcan be steered up to 50∘ in the elevation and the peak gain ismore than 160 dBiThe aperture efficiency of more than 50can be obtained The experiment validates the availability ofthe array design with mutual coupling considered

References

[1] S Yamamoto S Nuimura T Mizuno and Y Inasawa ldquoA Kuband small reflector antenna using backfire primary radiator forsatellite communication system on board vesselrdquo in Proceedingsof the International Symposium on Antennas and Propagation(ISAP rsquo12) pp 1273ndash1276 Nagoya Japan October 2012

12 International Journal of Antennas and Propagation

[2] J Thornton A White and G Long ldquoMulti-beam scanninglens antenna for satellite communications to trainsrdquoMicrowaveJournal vol 52 no 8 pp 56ndash70 2009

[3] A RWeily andNNikolic ldquoDual-polarized planar feed for low-profile hemispherical Luneburg lens antennasrdquo IEEE Transac-tions on Antennas and Propagation vol 60 no 1 pp 402ndash4072012

[4] S H Son and U H Park ldquoSidelobe reduction of low-profilearray antenna using a genetic algorithmrdquo ETRI Journal vol 29no 1 pp 95ndash98 2007

[5] PMousaviM Fakharzadeh S H Jamali et al ldquoA low-cost ultralow profile phased array system for mobile satellite receptionusing zero-knowledge beamforming algorithmrdquo IEEE Transac-tions on Antennas and Propagation vol 56 no 12 pp 3667ndash3679 2008

[6] S Vaccaro F Tiezzi M F Rua and C D G De Oro ldquoKu-BandLow-Profile Rx-only and Tx-Rx antennas for mobile satellitecommunicationsrdquo in Proceedings of the 4th IEEE InternationalSymposium on Phased Array Systems and Technology (Array rsquo10)pp 536ndash542 Waltham Mass USA October 2010

[7] R V Gatti L Marcaccioli E Sbarra and R SorrentinoldquoFlat array antennas for Ku-band mobile satellite terminalsrdquoInternational Journal of Antennas and Propagation vol 2009Article ID 836074 5 pages 2009

[8] C O Adler A D Monk D N Rasmussen and M J TaylorldquoTwo-way airborne broadband communications using phasedarray antennasrdquo in Proceedings of the IEEE Aerospace Confer-ence vol 2 pp 925ndash922 March 2003

[9] S Hasegawa T Yasuzumi O Hashimoto and Y KazamaldquoPolarization tracking phased array antenna with cross dipoleantenna-measured resultsrdquo in Proceedings of the IEEE Inter-national Symposium on Antennas and Propagation TorontoCanada July 2010

[10] J Zhou W Shi W B Dou and Y Shen ldquoHigh integratedmicrowave architecture using LTCC-SIP technology in activephased array antenna applicationsrdquo Frequenz vol 66 pp 177ndash182 2012

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

RoboticsJournal of

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Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Active and Passive Electronic Components

Control Scienceand Engineering

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

RotatingMachinery

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Submit your manuscripts athttpwwwhindawicom

VLSI Design

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Shock and Vibration

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Civil EngineeringAdvances in

Acoustics and VibrationAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Electrical and Computer Engineering

Journal of

Advances inOptoElectronics

Hindawi Publishing Corporation httpwwwhindawicom

Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

SensorsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chemical EngineeringInternational Journal of Antennas and

Propagation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Navigation and Observation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

DistributedSensor Networks

International Journal of

6 International Journal of Antennas and Propagation

190

185

180

175

170

165

Gai

n (d

Bi)

minus10 0 10 20 30 40 50 60Scan angle (deg)

Array B (final design)Array A (initial design)

(a) Horizontal polarization

190

185

180

175

170

Gai

n (d

Bi)

minus10 0 10 20 30 40 50 60Scan angle (deg)

Array B (final design)Array A (initial design)

(b) Vertical polarization

190

185

180

175

170

Gai

n (d

Bi)

minus10 0 10 20 30 40 50 60Scan angle (deg)

Array B (final design)Array A (initial design)

(c) Diagonal polarization

Figure 7 The comparison of gain during polarization tracking and beam scanning (azimuth angle 120593 = 0∘)

Figure 8 Front view of the fabricated array

International Journal of Antennas and Propagation 7

50

minus5

minus10

minus15

minus20

minus25

minus30

minus35

minus40

minus45

minus50

minus55

minus60

Relat

ive a

mpl

itude

(dB)

MeasuredSimulated

minus180 minus120 minus60 0 60 120 180Angle (deg)

(a) 120593 = 0∘ (H-plane)

50

minus5

minus10

minus15

minus20

minus25

minus30

minus35

minus40

minus45

minus50

Relat

ive a

mpl

itude

(dB)

MeasuredSimulated

minus180 minus120 minus60 0 60 120 180Angle (deg)

(b) 120593 = 90∘ (E-plane)

Figure 9 The active element pattern of central element R5-3 fed from port V

120572

p

h

(a) Polarization decomposition

Receiving element

Port VPort H

LNA 2LNA 1

Lange coupler

1205930 1205930 + Δ120593

Power combiner

1 2

3 4

(b) Schematic block diagram

Figure 10 The polarization tracking module for receiving application

Ground

Coplanar waveguide

Metalized via LTCC

OutputInput

Motherboard

Stripline

(a) Schematic diagram (b) Prototype

Figure 11 Transition from planar waveguide to stripline based on LTCC technology

8 International Journal of Antennas and Propagation

0

minus15

minus30

minus45

minus60

|S11|

(dB)

0 2 4 6 8 10 12 14 16 18Frequency (GHz)

00

minus25

minus50

minus75

minus100

Inse

rtio

n lo

ss (d

B)

MeasuredSimulated

Figure 12 Reflection coefficient and insertion loss of the LTCC-based vertical transition

(a) Top view (b) Bottom view

Figure 13 The fabricated compact polarization tracking module

measured reflection coefficient and insertion loss are plottedin Figure 12 It is observed that good agreement can beobtained between the simulated and measured results from2GHz to 18GHzThemeasured reflection coefficient is belowminus16 dB and the insertion loss is less than 15 dB We usedthe compact structure of the vertical transition to developa polarization tracking module integrated with multipleMMICs which is shown in Figure 13 With reference toFigure 10(b) the gain of two channels of the module wasmeasured with 120593

0= 0∘ when Δ120593 was increased from 0∘ to

minus360∘ with a step of minus5625∘ With reference to Figure 14the measured gain of both channels varies in the range fromabout 10 dB to 35 dBwith different trend which is determinedby the differential phase Δ120593 between two channels Thusthe different amplitude weighted coefficients for both port Vand port H can be achieved which results in the arbitrarylinear polarization of the antenna element With referenceto Figure 14 the diagonal polarization (120572 = 45∘ and 120572 =minus45∘) can be obtained due to the approximately same gain

of both channels with Δ120593 = 0∘ and minus180∘ The approximatevertical polarization can be obtained with Δ120593 = minus90∘ whenthe measured gains of port H and port V are about 105 dBand 337 dB The approximate horizontal polarization can beobtained with Δ120593 = minus270∘ when the measured gains of portH and port V are about 342 dB and 105 dB

4 Experiment Result

A small 7 times 7 polarization tracking active phased arraywas fabricated to cover the frequency range from 1225GHzto 1275GHz The inner 5 times 5 radiating elements are con-nected to the polarization tracking modules discussed aboveThe miniature 50Ω SMP female terminations are used asmatched loads directly connecting to the outermost 24passive radiating elements The schematic block diagram ofthe fabricated array is shown in Figure 15 The compact-ness of the polarization tracking module based on LTCC-SiP technology contributes to the low-profile phased arraywith the size of 120mm (length)times 120mm (width) times 55mm(height) The polarization tracking patterns were measuredin 119909119911-planeThe antenna prototype to be measured was fixedon the rotary platform in the microwave chamber and thepolarization can be controlled electronically without rotatingthe array aperture The patterns for horizontal vertical anddiagonal polarization can be measured respectively withΔ120593 = minus270

∘

minus90∘ and 0∘ The narrow bandwidth of

4 determines the stable radiation patterns over the entireoperating frequency range from 1225GHz to 1275GHzThus the polarization tracking patternsmeasured at 125GHzwith beam scanned to 0∘ 20∘ 40∘ and 50∘ are given inFigures 16 17 18 and 19 The reasonable agreement between

International Journal of Antennas and Propagation 9

40

35

30

25

20

15

10

5

Differential phase (deg)

Gai

n (d

B)

Port HPort V

0 minus45 minus90 minus135 minus180 minus225 minus270 minus315 minus360

Figure 14 The measured transmission gain versus the differential phase Δ120593 for port H and port V

Polarizationtrackingmodule

Polarizationtrackingmodule

Polarizationtrackingmodule

Polarizationtrackingmodule

Polarizationtrackingmodule

Power combiner network

Beam and polarizationcontroller

Antenna array

middot middot middot

middot middot middot

middot middot middot

Figure 15 The schematic block diagram of the fabricated polarization tracking active phased array

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB) 20 20

(a) Horizontal polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB) 20 20

(b) Vertical polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

MeasuredSimulated

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB) 20 20

(c) Diagonal polarization

Figure 16 The polarization tracking patterns measured at 125 GHz with beam scanned to 0∘

10 International Journal of Antennas and Propagation

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

(a) Horizontal polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB) 3

(b) Vertical polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

MeasuredSimulated

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

(c) Diagonal polarization

Figure 17 The polarization tracking patterns measured at 125 GHz with beam scanned to 20∘

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

0

0

minus60

minus50minus40

minus3020

3040

5060

7

8

(a) Horizontal polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

4

(b) Vertical polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

MeasuredSimulated

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

40

(c) Diagonal polarization

Figure 18 The polarization tracking patterns measured at 125 GHz with beam scanned to 40∘

the simulated and measured results can be observed Thesummary of the antenna prototype performance measured at125 GHz is provided in Table 2 wherein H V and D denotehorizontal vertical and diagonal polarization It is found thatthe mutual coupling results in the sidelobe level are greaterthan minus10 dB when the beam is steered to the angle greaterthan 40∘ Furthermore the beamwidth and beam pointingerror increase Table 2 gives the measured peak gain of the

polarization tracking array prototype during beam scanningand polarization tracking Compared with the simulatedresults small errors exist Since there are actually 5 times 5 activeradiating elements in the small 7 times 7 array the maximumdirectivity of the array is approximately 189 dBi Thus theaperture efficiency greater than 50 for the polarizationtracking array prototype can be evaluated according to themeasured peak gain

International Journal of Antennas and Propagation 11

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

50

(a) Horizontal polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

5

(b) Vertical polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

MeasuredSimulated

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

50

(c) Diagonal polarization

Figure 19 The polarization tracking patterns measured at 125 GHz with beam scanned to 50∘

Table 2 The measured data at 125 GHz for the developed small phased array prototype

Desired scan angle (deg) 0∘ 20∘ 40∘ 50∘

H V D H V D H V D H V DPeak gain (dBi)

Simulated 187 187 187 184 185 185 177 179 179 169 175 173Measured 183 185 182 179 177 180 172 174 175 161 163 162

Aperture efficiency () 87 91 85 79 76 81 68 71 72 52 55 53SLL (dB) minus133 minus118 minus113 minus123 minus133 minus106 minus113 minus84 minus60 minus79 minus88 minus74Half-power beam width (deg) 222∘ 213∘ 216∘ 219∘ 237 222∘ 243∘ 252∘ 243∘ 264∘ 249∘ 255∘

Beam pointing error (deg) 0 minus12∘ 3∘ minus14∘ 22∘ minus14∘ minus34∘ minus34∘ minus16∘ minus41∘ minus59∘ 13∘

5 Conclusion

We propose a compact polarization tracking active phasedarray for Ku-band satellite communicationThe phased arraywith the height of 55mm is suited to be used in the applicationstrictly limiting the profile of the antenna Based on thesimulated single radiating element a small 7 times 7 array modelwas established with the simulation tool CST MicrowaveStudio The outermost 24 elements are connected to 50Ωpassive loads which contributes to the 5 times 5 active array Thewhole array was simulated and the effects of mutual couplingon the impedance of the ports can be analyzed Based onthe dimensional parameters of the isolated antenna elementthe parameters were adjusted via numerous simulations Thefinal design with mutual coupling considered had loweractive reflection coefficient of minus15 dB with beam pointed tothe boresight of the array When the array operates in thestates of horizontal vertical and diagonal polarization thesimulated active reflection coefficients versus the scan anglefor central element are plotted Furthermore we propose a

compact LTCC-based polarization trackingmodule based ona vertical transition from planar waveguide to stripline Inthe frequency range from 1225GHz to 1275GHz a smallpolarization tracking active phased array prototypewas fabri-cated and its polarization can be configured electronically viathe proposed modules The measured polarization trackingpatterns for horizontal vertical and diagonal polarization aregiven It can be found from the measurement that the beamcan be steered up to 50∘ in the elevation and the peak gain ismore than 160 dBiThe aperture efficiency of more than 50can be obtained The experiment validates the availability ofthe array design with mutual coupling considered

References

[1] S Yamamoto S Nuimura T Mizuno and Y Inasawa ldquoA Kuband small reflector antenna using backfire primary radiator forsatellite communication system on board vesselrdquo in Proceedingsof the International Symposium on Antennas and Propagation(ISAP rsquo12) pp 1273ndash1276 Nagoya Japan October 2012

12 International Journal of Antennas and Propagation

[2] J Thornton A White and G Long ldquoMulti-beam scanninglens antenna for satellite communications to trainsrdquoMicrowaveJournal vol 52 no 8 pp 56ndash70 2009

[3] A RWeily andNNikolic ldquoDual-polarized planar feed for low-profile hemispherical Luneburg lens antennasrdquo IEEE Transac-tions on Antennas and Propagation vol 60 no 1 pp 402ndash4072012

[4] S H Son and U H Park ldquoSidelobe reduction of low-profilearray antenna using a genetic algorithmrdquo ETRI Journal vol 29no 1 pp 95ndash98 2007

[5] PMousaviM Fakharzadeh S H Jamali et al ldquoA low-cost ultralow profile phased array system for mobile satellite receptionusing zero-knowledge beamforming algorithmrdquo IEEE Transac-tions on Antennas and Propagation vol 56 no 12 pp 3667ndash3679 2008

[6] S Vaccaro F Tiezzi M F Rua and C D G De Oro ldquoKu-BandLow-Profile Rx-only and Tx-Rx antennas for mobile satellitecommunicationsrdquo in Proceedings of the 4th IEEE InternationalSymposium on Phased Array Systems and Technology (Array rsquo10)pp 536ndash542 Waltham Mass USA October 2010

[7] R V Gatti L Marcaccioli E Sbarra and R SorrentinoldquoFlat array antennas for Ku-band mobile satellite terminalsrdquoInternational Journal of Antennas and Propagation vol 2009Article ID 836074 5 pages 2009

[8] C O Adler A D Monk D N Rasmussen and M J TaylorldquoTwo-way airborne broadband communications using phasedarray antennasrdquo in Proceedings of the IEEE Aerospace Confer-ence vol 2 pp 925ndash922 March 2003

[9] S Hasegawa T Yasuzumi O Hashimoto and Y KazamaldquoPolarization tracking phased array antenna with cross dipoleantenna-measured resultsrdquo in Proceedings of the IEEE Inter-national Symposium on Antennas and Propagation TorontoCanada July 2010

[10] J Zhou W Shi W B Dou and Y Shen ldquoHigh integratedmicrowave architecture using LTCC-SIP technology in activephased array antenna applicationsrdquo Frequenz vol 66 pp 177ndash182 2012

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

RoboticsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Active and Passive Electronic Components

Control Scienceand Engineering

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

RotatingMachinery

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Submit your manuscripts athttpwwwhindawicom

VLSI Design

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Shock and Vibration

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Civil EngineeringAdvances in

Acoustics and VibrationAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Electrical and Computer Engineering

Journal of

Advances inOptoElectronics

Hindawi Publishing Corporation httpwwwhindawicom

Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

SensorsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chemical EngineeringInternational Journal of Antennas and

Propagation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Navigation and Observation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

DistributedSensor Networks

International Journal of

International Journal of Antennas and Propagation 7

50

minus5

minus10

minus15

minus20

minus25

minus30

minus35

minus40

minus45

minus50

minus55

minus60

Relat

ive a

mpl

itude

(dB)

MeasuredSimulated

minus180 minus120 minus60 0 60 120 180Angle (deg)

(a) 120593 = 0∘ (H-plane)

50

minus5

minus10

minus15

minus20

minus25

minus30

minus35

minus40

minus45

minus50

Relat

ive a

mpl

itude

(dB)

MeasuredSimulated

minus180 minus120 minus60 0 60 120 180Angle (deg)

(b) 120593 = 90∘ (E-plane)

Figure 9 The active element pattern of central element R5-3 fed from port V

120572

p

h

(a) Polarization decomposition

Receiving element

Port VPort H

LNA 2LNA 1

Lange coupler

1205930 1205930 + Δ120593

Power combiner

1 2

3 4

(b) Schematic block diagram

Figure 10 The polarization tracking module for receiving application

Ground

Coplanar waveguide

Metalized via LTCC

OutputInput

Motherboard

Stripline

(a) Schematic diagram (b) Prototype

Figure 11 Transition from planar waveguide to stripline based on LTCC technology

8 International Journal of Antennas and Propagation

0

minus15

minus30

minus45

minus60

|S11|

(dB)

0 2 4 6 8 10 12 14 16 18Frequency (GHz)

00

minus25

minus50

minus75

minus100

Inse

rtio

n lo

ss (d

B)

MeasuredSimulated

Figure 12 Reflection coefficient and insertion loss of the LTCC-based vertical transition

(a) Top view (b) Bottom view

Figure 13 The fabricated compact polarization tracking module

measured reflection coefficient and insertion loss are plottedin Figure 12 It is observed that good agreement can beobtained between the simulated and measured results from2GHz to 18GHzThemeasured reflection coefficient is belowminus16 dB and the insertion loss is less than 15 dB We usedthe compact structure of the vertical transition to developa polarization tracking module integrated with multipleMMICs which is shown in Figure 13 With reference toFigure 10(b) the gain of two channels of the module wasmeasured with 120593

0= 0∘ when Δ120593 was increased from 0∘ to

minus360∘ with a step of minus5625∘ With reference to Figure 14the measured gain of both channels varies in the range fromabout 10 dB to 35 dBwith different trend which is determinedby the differential phase Δ120593 between two channels Thusthe different amplitude weighted coefficients for both port Vand port H can be achieved which results in the arbitrarylinear polarization of the antenna element With referenceto Figure 14 the diagonal polarization (120572 = 45∘ and 120572 =minus45∘) can be obtained due to the approximately same gain

of both channels with Δ120593 = 0∘ and minus180∘ The approximatevertical polarization can be obtained with Δ120593 = minus90∘ whenthe measured gains of port H and port V are about 105 dBand 337 dB The approximate horizontal polarization can beobtained with Δ120593 = minus270∘ when the measured gains of portH and port V are about 342 dB and 105 dB

4 Experiment Result

A small 7 times 7 polarization tracking active phased arraywas fabricated to cover the frequency range from 1225GHzto 1275GHz The inner 5 times 5 radiating elements are con-nected to the polarization tracking modules discussed aboveThe miniature 50Ω SMP female terminations are used asmatched loads directly connecting to the outermost 24passive radiating elements The schematic block diagram ofthe fabricated array is shown in Figure 15 The compact-ness of the polarization tracking module based on LTCC-SiP technology contributes to the low-profile phased arraywith the size of 120mm (length)times 120mm (width) times 55mm(height) The polarization tracking patterns were measuredin 119909119911-planeThe antenna prototype to be measured was fixedon the rotary platform in the microwave chamber and thepolarization can be controlled electronically without rotatingthe array aperture The patterns for horizontal vertical anddiagonal polarization can be measured respectively withΔ120593 = minus270

∘

minus90∘ and 0∘ The narrow bandwidth of

4 determines the stable radiation patterns over the entireoperating frequency range from 1225GHz to 1275GHzThus the polarization tracking patternsmeasured at 125GHzwith beam scanned to 0∘ 20∘ 40∘ and 50∘ are given inFigures 16 17 18 and 19 The reasonable agreement between

International Journal of Antennas and Propagation 9

40

35

30

25

20

15

10

5

Differential phase (deg)

Gai

n (d

B)

Port HPort V

0 minus45 minus90 minus135 minus180 minus225 minus270 minus315 minus360

Figure 14 The measured transmission gain versus the differential phase Δ120593 for port H and port V

Polarizationtrackingmodule

Polarizationtrackingmodule

Polarizationtrackingmodule

Polarizationtrackingmodule

Polarizationtrackingmodule

Power combiner network

Beam and polarizationcontroller

Antenna array

middot middot middot

middot middot middot

middot middot middot

Figure 15 The schematic block diagram of the fabricated polarization tracking active phased array

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB) 20 20

(a) Horizontal polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB) 20 20

(b) Vertical polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

MeasuredSimulated

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB) 20 20

(c) Diagonal polarization

Figure 16 The polarization tracking patterns measured at 125 GHz with beam scanned to 0∘

10 International Journal of Antennas and Propagation

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

(a) Horizontal polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB) 3

(b) Vertical polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

MeasuredSimulated

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

(c) Diagonal polarization

Figure 17 The polarization tracking patterns measured at 125 GHz with beam scanned to 20∘

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

0

0

minus60

minus50minus40

minus3020

3040

5060

7

8

(a) Horizontal polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

4

(b) Vertical polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

MeasuredSimulated

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

40

(c) Diagonal polarization

Figure 18 The polarization tracking patterns measured at 125 GHz with beam scanned to 40∘

the simulated and measured results can be observed Thesummary of the antenna prototype performance measured at125 GHz is provided in Table 2 wherein H V and D denotehorizontal vertical and diagonal polarization It is found thatthe mutual coupling results in the sidelobe level are greaterthan minus10 dB when the beam is steered to the angle greaterthan 40∘ Furthermore the beamwidth and beam pointingerror increase Table 2 gives the measured peak gain of the

polarization tracking array prototype during beam scanningand polarization tracking Compared with the simulatedresults small errors exist Since there are actually 5 times 5 activeradiating elements in the small 7 times 7 array the maximumdirectivity of the array is approximately 189 dBi Thus theaperture efficiency greater than 50 for the polarizationtracking array prototype can be evaluated according to themeasured peak gain

International Journal of Antennas and Propagation 11

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

50

(a) Horizontal polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

5

(b) Vertical polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

MeasuredSimulated

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

50

(c) Diagonal polarization

Figure 19 The polarization tracking patterns measured at 125 GHz with beam scanned to 50∘

Table 2 The measured data at 125 GHz for the developed small phased array prototype

Desired scan angle (deg) 0∘ 20∘ 40∘ 50∘

H V D H V D H V D H V DPeak gain (dBi)

Simulated 187 187 187 184 185 185 177 179 179 169 175 173Measured 183 185 182 179 177 180 172 174 175 161 163 162

Aperture efficiency () 87 91 85 79 76 81 68 71 72 52 55 53SLL (dB) minus133 minus118 minus113 minus123 minus133 minus106 minus113 minus84 minus60 minus79 minus88 minus74Half-power beam width (deg) 222∘ 213∘ 216∘ 219∘ 237 222∘ 243∘ 252∘ 243∘ 264∘ 249∘ 255∘

Beam pointing error (deg) 0 minus12∘ 3∘ minus14∘ 22∘ minus14∘ minus34∘ minus34∘ minus16∘ minus41∘ minus59∘ 13∘

5 Conclusion

We propose a compact polarization tracking active phasedarray for Ku-band satellite communicationThe phased arraywith the height of 55mm is suited to be used in the applicationstrictly limiting the profile of the antenna Based on thesimulated single radiating element a small 7 times 7 array modelwas established with the simulation tool CST MicrowaveStudio The outermost 24 elements are connected to 50Ωpassive loads which contributes to the 5 times 5 active array Thewhole array was simulated and the effects of mutual couplingon the impedance of the ports can be analyzed Based onthe dimensional parameters of the isolated antenna elementthe parameters were adjusted via numerous simulations Thefinal design with mutual coupling considered had loweractive reflection coefficient of minus15 dB with beam pointed tothe boresight of the array When the array operates in thestates of horizontal vertical and diagonal polarization thesimulated active reflection coefficients versus the scan anglefor central element are plotted Furthermore we propose a

compact LTCC-based polarization trackingmodule based ona vertical transition from planar waveguide to stripline Inthe frequency range from 1225GHz to 1275GHz a smallpolarization tracking active phased array prototypewas fabri-cated and its polarization can be configured electronically viathe proposed modules The measured polarization trackingpatterns for horizontal vertical and diagonal polarization aregiven It can be found from the measurement that the beamcan be steered up to 50∘ in the elevation and the peak gain ismore than 160 dBiThe aperture efficiency of more than 50can be obtained The experiment validates the availability ofthe array design with mutual coupling considered

References

[1] S Yamamoto S Nuimura T Mizuno and Y Inasawa ldquoA Kuband small reflector antenna using backfire primary radiator forsatellite communication system on board vesselrdquo in Proceedingsof the International Symposium on Antennas and Propagation(ISAP rsquo12) pp 1273ndash1276 Nagoya Japan October 2012

12 International Journal of Antennas and Propagation

[2] J Thornton A White and G Long ldquoMulti-beam scanninglens antenna for satellite communications to trainsrdquoMicrowaveJournal vol 52 no 8 pp 56ndash70 2009

[3] A RWeily andNNikolic ldquoDual-polarized planar feed for low-profile hemispherical Luneburg lens antennasrdquo IEEE Transac-tions on Antennas and Propagation vol 60 no 1 pp 402ndash4072012

[4] S H Son and U H Park ldquoSidelobe reduction of low-profilearray antenna using a genetic algorithmrdquo ETRI Journal vol 29no 1 pp 95ndash98 2007

[5] PMousaviM Fakharzadeh S H Jamali et al ldquoA low-cost ultralow profile phased array system for mobile satellite receptionusing zero-knowledge beamforming algorithmrdquo IEEE Transac-tions on Antennas and Propagation vol 56 no 12 pp 3667ndash3679 2008

[6] S Vaccaro F Tiezzi M F Rua and C D G De Oro ldquoKu-BandLow-Profile Rx-only and Tx-Rx antennas for mobile satellitecommunicationsrdquo in Proceedings of the 4th IEEE InternationalSymposium on Phased Array Systems and Technology (Array rsquo10)pp 536ndash542 Waltham Mass USA October 2010

[7] R V Gatti L Marcaccioli E Sbarra and R SorrentinoldquoFlat array antennas for Ku-band mobile satellite terminalsrdquoInternational Journal of Antennas and Propagation vol 2009Article ID 836074 5 pages 2009

[8] C O Adler A D Monk D N Rasmussen and M J TaylorldquoTwo-way airborne broadband communications using phasedarray antennasrdquo in Proceedings of the IEEE Aerospace Confer-ence vol 2 pp 925ndash922 March 2003

[9] S Hasegawa T Yasuzumi O Hashimoto and Y KazamaldquoPolarization tracking phased array antenna with cross dipoleantenna-measured resultsrdquo in Proceedings of the IEEE Inter-national Symposium on Antennas and Propagation TorontoCanada July 2010

[10] J Zhou W Shi W B Dou and Y Shen ldquoHigh integratedmicrowave architecture using LTCC-SIP technology in activephased array antenna applicationsrdquo Frequenz vol 66 pp 177ndash182 2012

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

RoboticsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Active and Passive Electronic Components

Control Scienceand Engineering

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

RotatingMachinery

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Submit your manuscripts athttpwwwhindawicom

VLSI Design

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Shock and Vibration

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Civil EngineeringAdvances in

Acoustics and VibrationAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Electrical and Computer Engineering

Journal of

Advances inOptoElectronics

Hindawi Publishing Corporation httpwwwhindawicom

Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

SensorsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chemical EngineeringInternational Journal of Antennas and

Propagation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Navigation and Observation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

DistributedSensor Networks

International Journal of

8 International Journal of Antennas and Propagation

0

minus15

minus30

minus45

minus60

|S11|

(dB)

0 2 4 6 8 10 12 14 16 18Frequency (GHz)

00

minus25

minus50

minus75

minus100

Inse

rtio

n lo

ss (d

B)

MeasuredSimulated

Figure 12 Reflection coefficient and insertion loss of the LTCC-based vertical transition

(a) Top view (b) Bottom view

Figure 13 The fabricated compact polarization tracking module

measured reflection coefficient and insertion loss are plottedin Figure 12 It is observed that good agreement can beobtained between the simulated and measured results from2GHz to 18GHzThemeasured reflection coefficient is belowminus16 dB and the insertion loss is less than 15 dB We usedthe compact structure of the vertical transition to developa polarization tracking module integrated with multipleMMICs which is shown in Figure 13 With reference toFigure 10(b) the gain of two channels of the module wasmeasured with 120593

0= 0∘ when Δ120593 was increased from 0∘ to

minus360∘ with a step of minus5625∘ With reference to Figure 14the measured gain of both channels varies in the range fromabout 10 dB to 35 dBwith different trend which is determinedby the differential phase Δ120593 between two channels Thusthe different amplitude weighted coefficients for both port Vand port H can be achieved which results in the arbitrarylinear polarization of the antenna element With referenceto Figure 14 the diagonal polarization (120572 = 45∘ and 120572 =minus45∘) can be obtained due to the approximately same gain

of both channels with Δ120593 = 0∘ and minus180∘ The approximatevertical polarization can be obtained with Δ120593 = minus90∘ whenthe measured gains of port H and port V are about 105 dBand 337 dB The approximate horizontal polarization can beobtained with Δ120593 = minus270∘ when the measured gains of portH and port V are about 342 dB and 105 dB

4 Experiment Result

A small 7 times 7 polarization tracking active phased arraywas fabricated to cover the frequency range from 1225GHzto 1275GHz The inner 5 times 5 radiating elements are con-nected to the polarization tracking modules discussed aboveThe miniature 50Ω SMP female terminations are used asmatched loads directly connecting to the outermost 24passive radiating elements The schematic block diagram ofthe fabricated array is shown in Figure 15 The compact-ness of the polarization tracking module based on LTCC-SiP technology contributes to the low-profile phased arraywith the size of 120mm (length)times 120mm (width) times 55mm(height) The polarization tracking patterns were measuredin 119909119911-planeThe antenna prototype to be measured was fixedon the rotary platform in the microwave chamber and thepolarization can be controlled electronically without rotatingthe array aperture The patterns for horizontal vertical anddiagonal polarization can be measured respectively withΔ120593 = minus270

∘

minus90∘ and 0∘ The narrow bandwidth of

4 determines the stable radiation patterns over the entireoperating frequency range from 1225GHz to 1275GHzThus the polarization tracking patternsmeasured at 125GHzwith beam scanned to 0∘ 20∘ 40∘ and 50∘ are given inFigures 16 17 18 and 19 The reasonable agreement between

International Journal of Antennas and Propagation 9

40

35

30

25

20

15

10

5

Differential phase (deg)

Gai

n (d

B)

Port HPort V

0 minus45 minus90 minus135 minus180 minus225 minus270 minus315 minus360

Figure 14 The measured transmission gain versus the differential phase Δ120593 for port H and port V

Polarizationtrackingmodule

Polarizationtrackingmodule

Polarizationtrackingmodule

Polarizationtrackingmodule

Polarizationtrackingmodule

Power combiner network

Beam and polarizationcontroller

Antenna array

middot middot middot

middot middot middot

middot middot middot

Figure 15 The schematic block diagram of the fabricated polarization tracking active phased array

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB) 20 20

(a) Horizontal polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB) 20 20

(b) Vertical polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

MeasuredSimulated

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB) 20 20

(c) Diagonal polarization

Figure 16 The polarization tracking patterns measured at 125 GHz with beam scanned to 0∘

10 International Journal of Antennas and Propagation

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

(a) Horizontal polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB) 3

(b) Vertical polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

MeasuredSimulated

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

(c) Diagonal polarization

Figure 17 The polarization tracking patterns measured at 125 GHz with beam scanned to 20∘

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

0

0

minus60

minus50minus40

minus3020

3040

5060

7

8

(a) Horizontal polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

4

(b) Vertical polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

MeasuredSimulated

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

40

(c) Diagonal polarization

Figure 18 The polarization tracking patterns measured at 125 GHz with beam scanned to 40∘

the simulated and measured results can be observed Thesummary of the antenna prototype performance measured at125 GHz is provided in Table 2 wherein H V and D denotehorizontal vertical and diagonal polarization It is found thatthe mutual coupling results in the sidelobe level are greaterthan minus10 dB when the beam is steered to the angle greaterthan 40∘ Furthermore the beamwidth and beam pointingerror increase Table 2 gives the measured peak gain of the

polarization tracking array prototype during beam scanningand polarization tracking Compared with the simulatedresults small errors exist Since there are actually 5 times 5 activeradiating elements in the small 7 times 7 array the maximumdirectivity of the array is approximately 189 dBi Thus theaperture efficiency greater than 50 for the polarizationtracking array prototype can be evaluated according to themeasured peak gain

International Journal of Antennas and Propagation 11

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

50

(a) Horizontal polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

5

(b) Vertical polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

MeasuredSimulated

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

50

(c) Diagonal polarization

Figure 19 The polarization tracking patterns measured at 125 GHz with beam scanned to 50∘

Table 2 The measured data at 125 GHz for the developed small phased array prototype

Desired scan angle (deg) 0∘ 20∘ 40∘ 50∘

H V D H V D H V D H V DPeak gain (dBi)

Simulated 187 187 187 184 185 185 177 179 179 169 175 173Measured 183 185 182 179 177 180 172 174 175 161 163 162

Aperture efficiency () 87 91 85 79 76 81 68 71 72 52 55 53SLL (dB) minus133 minus118 minus113 minus123 minus133 minus106 minus113 minus84 minus60 minus79 minus88 minus74Half-power beam width (deg) 222∘ 213∘ 216∘ 219∘ 237 222∘ 243∘ 252∘ 243∘ 264∘ 249∘ 255∘

Beam pointing error (deg) 0 minus12∘ 3∘ minus14∘ 22∘ minus14∘ minus34∘ minus34∘ minus16∘ minus41∘ minus59∘ 13∘

5 Conclusion

We propose a compact polarization tracking active phasedarray for Ku-band satellite communicationThe phased arraywith the height of 55mm is suited to be used in the applicationstrictly limiting the profile of the antenna Based on thesimulated single radiating element a small 7 times 7 array modelwas established with the simulation tool CST MicrowaveStudio The outermost 24 elements are connected to 50Ωpassive loads which contributes to the 5 times 5 active array Thewhole array was simulated and the effects of mutual couplingon the impedance of the ports can be analyzed Based onthe dimensional parameters of the isolated antenna elementthe parameters were adjusted via numerous simulations Thefinal design with mutual coupling considered had loweractive reflection coefficient of minus15 dB with beam pointed tothe boresight of the array When the array operates in thestates of horizontal vertical and diagonal polarization thesimulated active reflection coefficients versus the scan anglefor central element are plotted Furthermore we propose a

compact LTCC-based polarization trackingmodule based ona vertical transition from planar waveguide to stripline Inthe frequency range from 1225GHz to 1275GHz a smallpolarization tracking active phased array prototypewas fabri-cated and its polarization can be configured electronically viathe proposed modules The measured polarization trackingpatterns for horizontal vertical and diagonal polarization aregiven It can be found from the measurement that the beamcan be steered up to 50∘ in the elevation and the peak gain ismore than 160 dBiThe aperture efficiency of more than 50can be obtained The experiment validates the availability ofthe array design with mutual coupling considered

References

[1] S Yamamoto S Nuimura T Mizuno and Y Inasawa ldquoA Kuband small reflector antenna using backfire primary radiator forsatellite communication system on board vesselrdquo in Proceedingsof the International Symposium on Antennas and Propagation(ISAP rsquo12) pp 1273ndash1276 Nagoya Japan October 2012

12 International Journal of Antennas and Propagation

[2] J Thornton A White and G Long ldquoMulti-beam scanninglens antenna for satellite communications to trainsrdquoMicrowaveJournal vol 52 no 8 pp 56ndash70 2009

[3] A RWeily andNNikolic ldquoDual-polarized planar feed for low-profile hemispherical Luneburg lens antennasrdquo IEEE Transac-tions on Antennas and Propagation vol 60 no 1 pp 402ndash4072012

[4] S H Son and U H Park ldquoSidelobe reduction of low-profilearray antenna using a genetic algorithmrdquo ETRI Journal vol 29no 1 pp 95ndash98 2007

[5] PMousaviM Fakharzadeh S H Jamali et al ldquoA low-cost ultralow profile phased array system for mobile satellite receptionusing zero-knowledge beamforming algorithmrdquo IEEE Transac-tions on Antennas and Propagation vol 56 no 12 pp 3667ndash3679 2008

[6] S Vaccaro F Tiezzi M F Rua and C D G De Oro ldquoKu-BandLow-Profile Rx-only and Tx-Rx antennas for mobile satellitecommunicationsrdquo in Proceedings of the 4th IEEE InternationalSymposium on Phased Array Systems and Technology (Array rsquo10)pp 536ndash542 Waltham Mass USA October 2010

[7] R V Gatti L Marcaccioli E Sbarra and R SorrentinoldquoFlat array antennas for Ku-band mobile satellite terminalsrdquoInternational Journal of Antennas and Propagation vol 2009Article ID 836074 5 pages 2009

[8] C O Adler A D Monk D N Rasmussen and M J TaylorldquoTwo-way airborne broadband communications using phasedarray antennasrdquo in Proceedings of the IEEE Aerospace Confer-ence vol 2 pp 925ndash922 March 2003

[9] S Hasegawa T Yasuzumi O Hashimoto and Y KazamaldquoPolarization tracking phased array antenna with cross dipoleantenna-measured resultsrdquo in Proceedings of the IEEE Inter-national Symposium on Antennas and Propagation TorontoCanada July 2010

[10] J Zhou W Shi W B Dou and Y Shen ldquoHigh integratedmicrowave architecture using LTCC-SIP technology in activephased array antenna applicationsrdquo Frequenz vol 66 pp 177ndash182 2012

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

RoboticsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Active and Passive Electronic Components

Control Scienceand Engineering

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

RotatingMachinery

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Submit your manuscripts athttpwwwhindawicom

VLSI Design

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Shock and Vibration

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Civil EngineeringAdvances in

Acoustics and VibrationAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Electrical and Computer Engineering

Journal of

Advances inOptoElectronics

Hindawi Publishing Corporation httpwwwhindawicom

Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

SensorsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chemical EngineeringInternational Journal of Antennas and

Propagation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Navigation and Observation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

DistributedSensor Networks

International Journal of

International Journal of Antennas and Propagation 9

40

35

30

25

20

15

10

5

Differential phase (deg)

Gai

n (d

B)

Port HPort V

0 minus45 minus90 minus135 minus180 minus225 minus270 minus315 minus360

Figure 14 The measured transmission gain versus the differential phase Δ120593 for port H and port V

Polarizationtrackingmodule

Polarizationtrackingmodule

Polarizationtrackingmodule

Polarizationtrackingmodule

Polarizationtrackingmodule

Power combiner network

Beam and polarizationcontroller

Antenna array

middot middot middot

middot middot middot

middot middot middot

Figure 15 The schematic block diagram of the fabricated polarization tracking active phased array

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB) 20 20

(a) Horizontal polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB) 20 20

(b) Vertical polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

MeasuredSimulated

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB) 20 20

(c) Diagonal polarization

Figure 16 The polarization tracking patterns measured at 125 GHz with beam scanned to 0∘

10 International Journal of Antennas and Propagation

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

(a) Horizontal polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB) 3

(b) Vertical polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

MeasuredSimulated

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

(c) Diagonal polarization

Figure 17 The polarization tracking patterns measured at 125 GHz with beam scanned to 20∘

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

0

0

minus60

minus50minus40

minus3020

3040

5060

7

8

(a) Horizontal polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

4

(b) Vertical polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

MeasuredSimulated

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

40

(c) Diagonal polarization

Figure 18 The polarization tracking patterns measured at 125 GHz with beam scanned to 40∘

the simulated and measured results can be observed Thesummary of the antenna prototype performance measured at125 GHz is provided in Table 2 wherein H V and D denotehorizontal vertical and diagonal polarization It is found thatthe mutual coupling results in the sidelobe level are greaterthan minus10 dB when the beam is steered to the angle greaterthan 40∘ Furthermore the beamwidth and beam pointingerror increase Table 2 gives the measured peak gain of the

polarization tracking array prototype during beam scanningand polarization tracking Compared with the simulatedresults small errors exist Since there are actually 5 times 5 activeradiating elements in the small 7 times 7 array the maximumdirectivity of the array is approximately 189 dBi Thus theaperture efficiency greater than 50 for the polarizationtracking array prototype can be evaluated according to themeasured peak gain

International Journal of Antennas and Propagation 11

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

50

(a) Horizontal polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

5

(b) Vertical polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

MeasuredSimulated

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

50

(c) Diagonal polarization

Figure 19 The polarization tracking patterns measured at 125 GHz with beam scanned to 50∘

Table 2 The measured data at 125 GHz for the developed small phased array prototype

Desired scan angle (deg) 0∘ 20∘ 40∘ 50∘

H V D H V D H V D H V DPeak gain (dBi)

Simulated 187 187 187 184 185 185 177 179 179 169 175 173Measured 183 185 182 179 177 180 172 174 175 161 163 162

Aperture efficiency () 87 91 85 79 76 81 68 71 72 52 55 53SLL (dB) minus133 minus118 minus113 minus123 minus133 minus106 minus113 minus84 minus60 minus79 minus88 minus74Half-power beam width (deg) 222∘ 213∘ 216∘ 219∘ 237 222∘ 243∘ 252∘ 243∘ 264∘ 249∘ 255∘

Beam pointing error (deg) 0 minus12∘ 3∘ minus14∘ 22∘ minus14∘ minus34∘ minus34∘ minus16∘ minus41∘ minus59∘ 13∘

5 Conclusion

We propose a compact polarization tracking active phasedarray for Ku-band satellite communicationThe phased arraywith the height of 55mm is suited to be used in the applicationstrictly limiting the profile of the antenna Based on thesimulated single radiating element a small 7 times 7 array modelwas established with the simulation tool CST MicrowaveStudio The outermost 24 elements are connected to 50Ωpassive loads which contributes to the 5 times 5 active array Thewhole array was simulated and the effects of mutual couplingon the impedance of the ports can be analyzed Based onthe dimensional parameters of the isolated antenna elementthe parameters were adjusted via numerous simulations Thefinal design with mutual coupling considered had loweractive reflection coefficient of minus15 dB with beam pointed tothe boresight of the array When the array operates in thestates of horizontal vertical and diagonal polarization thesimulated active reflection coefficients versus the scan anglefor central element are plotted Furthermore we propose a

compact LTCC-based polarization trackingmodule based ona vertical transition from planar waveguide to stripline Inthe frequency range from 1225GHz to 1275GHz a smallpolarization tracking active phased array prototypewas fabri-cated and its polarization can be configured electronically viathe proposed modules The measured polarization trackingpatterns for horizontal vertical and diagonal polarization aregiven It can be found from the measurement that the beamcan be steered up to 50∘ in the elevation and the peak gain ismore than 160 dBiThe aperture efficiency of more than 50can be obtained The experiment validates the availability ofthe array design with mutual coupling considered

References

[1] S Yamamoto S Nuimura T Mizuno and Y Inasawa ldquoA Kuband small reflector antenna using backfire primary radiator forsatellite communication system on board vesselrdquo in Proceedingsof the International Symposium on Antennas and Propagation(ISAP rsquo12) pp 1273ndash1276 Nagoya Japan October 2012

12 International Journal of Antennas and Propagation

[2] J Thornton A White and G Long ldquoMulti-beam scanninglens antenna for satellite communications to trainsrdquoMicrowaveJournal vol 52 no 8 pp 56ndash70 2009

[3] A RWeily andNNikolic ldquoDual-polarized planar feed for low-profile hemispherical Luneburg lens antennasrdquo IEEE Transac-tions on Antennas and Propagation vol 60 no 1 pp 402ndash4072012

[4] S H Son and U H Park ldquoSidelobe reduction of low-profilearray antenna using a genetic algorithmrdquo ETRI Journal vol 29no 1 pp 95ndash98 2007

[5] PMousaviM Fakharzadeh S H Jamali et al ldquoA low-cost ultralow profile phased array system for mobile satellite receptionusing zero-knowledge beamforming algorithmrdquo IEEE Transac-tions on Antennas and Propagation vol 56 no 12 pp 3667ndash3679 2008

[6] S Vaccaro F Tiezzi M F Rua and C D G De Oro ldquoKu-BandLow-Profile Rx-only and Tx-Rx antennas for mobile satellitecommunicationsrdquo in Proceedings of the 4th IEEE InternationalSymposium on Phased Array Systems and Technology (Array rsquo10)pp 536ndash542 Waltham Mass USA October 2010

[7] R V Gatti L Marcaccioli E Sbarra and R SorrentinoldquoFlat array antennas for Ku-band mobile satellite terminalsrdquoInternational Journal of Antennas and Propagation vol 2009Article ID 836074 5 pages 2009

[8] C O Adler A D Monk D N Rasmussen and M J TaylorldquoTwo-way airborne broadband communications using phasedarray antennasrdquo in Proceedings of the IEEE Aerospace Confer-ence vol 2 pp 925ndash922 March 2003

[9] S Hasegawa T Yasuzumi O Hashimoto and Y KazamaldquoPolarization tracking phased array antenna with cross dipoleantenna-measured resultsrdquo in Proceedings of the IEEE Inter-national Symposium on Antennas and Propagation TorontoCanada July 2010

[10] J Zhou W Shi W B Dou and Y Shen ldquoHigh integratedmicrowave architecture using LTCC-SIP technology in activephased array antenna applicationsrdquo Frequenz vol 66 pp 177ndash182 2012

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

RoboticsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Active and Passive Electronic Components

Control Scienceand Engineering

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

RotatingMachinery

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Submit your manuscripts athttpwwwhindawicom

VLSI Design

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Shock and Vibration

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Civil EngineeringAdvances in

Acoustics and VibrationAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Electrical and Computer Engineering

Journal of

Advances inOptoElectronics

Hindawi Publishing Corporation httpwwwhindawicom

Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

SensorsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chemical EngineeringInternational Journal of Antennas and

Propagation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Navigation and Observation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

DistributedSensor Networks

International Journal of

10 International Journal of Antennas and Propagation

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

(a) Horizontal polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB) 3

(b) Vertical polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

MeasuredSimulated

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

(c) Diagonal polarization

Figure 17 The polarization tracking patterns measured at 125 GHz with beam scanned to 20∘

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

0

0

minus60

minus50minus40

minus3020

3040

5060

7

8

(a) Horizontal polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

4

(b) Vertical polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

MeasuredSimulated

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

40

(c) Diagonal polarization

Figure 18 The polarization tracking patterns measured at 125 GHz with beam scanned to 40∘

the simulated and measured results can be observed Thesummary of the antenna prototype performance measured at125 GHz is provided in Table 2 wherein H V and D denotehorizontal vertical and diagonal polarization It is found thatthe mutual coupling results in the sidelobe level are greaterthan minus10 dB when the beam is steered to the angle greaterthan 40∘ Furthermore the beamwidth and beam pointingerror increase Table 2 gives the measured peak gain of the

polarization tracking array prototype during beam scanningand polarization tracking Compared with the simulatedresults small errors exist Since there are actually 5 times 5 activeradiating elements in the small 7 times 7 array the maximumdirectivity of the array is approximately 189 dBi Thus theaperture efficiency greater than 50 for the polarizationtracking array prototype can be evaluated according to themeasured peak gain

International Journal of Antennas and Propagation 11

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

50

(a) Horizontal polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

5

(b) Vertical polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

MeasuredSimulated

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

50

(c) Diagonal polarization

Figure 19 The polarization tracking patterns measured at 125 GHz with beam scanned to 50∘

Table 2 The measured data at 125 GHz for the developed small phased array prototype

Desired scan angle (deg) 0∘ 20∘ 40∘ 50∘

H V D H V D H V D H V DPeak gain (dBi)

Simulated 187 187 187 184 185 185 177 179 179 169 175 173Measured 183 185 182 179 177 180 172 174 175 161 163 162

Aperture efficiency () 87 91 85 79 76 81 68 71 72 52 55 53SLL (dB) minus133 minus118 minus113 minus123 minus133 minus106 minus113 minus84 minus60 minus79 minus88 minus74Half-power beam width (deg) 222∘ 213∘ 216∘ 219∘ 237 222∘ 243∘ 252∘ 243∘ 264∘ 249∘ 255∘

Beam pointing error (deg) 0 minus12∘ 3∘ minus14∘ 22∘ minus14∘ minus34∘ minus34∘ minus16∘ minus41∘ minus59∘ 13∘

5 Conclusion

We propose a compact polarization tracking active phasedarray for Ku-band satellite communicationThe phased arraywith the height of 55mm is suited to be used in the applicationstrictly limiting the profile of the antenna Based on thesimulated single radiating element a small 7 times 7 array modelwas established with the simulation tool CST MicrowaveStudio The outermost 24 elements are connected to 50Ωpassive loads which contributes to the 5 times 5 active array Thewhole array was simulated and the effects of mutual couplingon the impedance of the ports can be analyzed Based onthe dimensional parameters of the isolated antenna elementthe parameters were adjusted via numerous simulations Thefinal design with mutual coupling considered had loweractive reflection coefficient of minus15 dB with beam pointed tothe boresight of the array When the array operates in thestates of horizontal vertical and diagonal polarization thesimulated active reflection coefficients versus the scan anglefor central element are plotted Furthermore we propose a

compact LTCC-based polarization trackingmodule based ona vertical transition from planar waveguide to stripline Inthe frequency range from 1225GHz to 1275GHz a smallpolarization tracking active phased array prototypewas fabri-cated and its polarization can be configured electronically viathe proposed modules The measured polarization trackingpatterns for horizontal vertical and diagonal polarization aregiven It can be found from the measurement that the beamcan be steered up to 50∘ in the elevation and the peak gain ismore than 160 dBiThe aperture efficiency of more than 50can be obtained The experiment validates the availability ofthe array design with mutual coupling considered

References

[1] S Yamamoto S Nuimura T Mizuno and Y Inasawa ldquoA Kuband small reflector antenna using backfire primary radiator forsatellite communication system on board vesselrdquo in Proceedingsof the International Symposium on Antennas and Propagation(ISAP rsquo12) pp 1273ndash1276 Nagoya Japan October 2012

12 International Journal of Antennas and Propagation

[2] J Thornton A White and G Long ldquoMulti-beam scanninglens antenna for satellite communications to trainsrdquoMicrowaveJournal vol 52 no 8 pp 56ndash70 2009

[3] A RWeily andNNikolic ldquoDual-polarized planar feed for low-profile hemispherical Luneburg lens antennasrdquo IEEE Transac-tions on Antennas and Propagation vol 60 no 1 pp 402ndash4072012

[4] S H Son and U H Park ldquoSidelobe reduction of low-profilearray antenna using a genetic algorithmrdquo ETRI Journal vol 29no 1 pp 95ndash98 2007

[5] PMousaviM Fakharzadeh S H Jamali et al ldquoA low-cost ultralow profile phased array system for mobile satellite receptionusing zero-knowledge beamforming algorithmrdquo IEEE Transac-tions on Antennas and Propagation vol 56 no 12 pp 3667ndash3679 2008

[6] S Vaccaro F Tiezzi M F Rua and C D G De Oro ldquoKu-BandLow-Profile Rx-only and Tx-Rx antennas for mobile satellitecommunicationsrdquo in Proceedings of the 4th IEEE InternationalSymposium on Phased Array Systems and Technology (Array rsquo10)pp 536ndash542 Waltham Mass USA October 2010

[7] R V Gatti L Marcaccioli E Sbarra and R SorrentinoldquoFlat array antennas for Ku-band mobile satellite terminalsrdquoInternational Journal of Antennas and Propagation vol 2009Article ID 836074 5 pages 2009

[8] C O Adler A D Monk D N Rasmussen and M J TaylorldquoTwo-way airborne broadband communications using phasedarray antennasrdquo in Proceedings of the IEEE Aerospace Confer-ence vol 2 pp 925ndash922 March 2003

[9] S Hasegawa T Yasuzumi O Hashimoto and Y KazamaldquoPolarization tracking phased array antenna with cross dipoleantenna-measured resultsrdquo in Proceedings of the IEEE Inter-national Symposium on Antennas and Propagation TorontoCanada July 2010

[10] J Zhou W Shi W B Dou and Y Shen ldquoHigh integratedmicrowave architecture using LTCC-SIP technology in activephased array antenna applicationsrdquo Frequenz vol 66 pp 177ndash182 2012

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

RoboticsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Active and Passive Electronic Components

Control Scienceand Engineering

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

RotatingMachinery

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Submit your manuscripts athttpwwwhindawicom

VLSI Design

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Shock and Vibration

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Civil EngineeringAdvances in

Acoustics and VibrationAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Electrical and Computer Engineering

Journal of

Advances inOptoElectronics

Hindawi Publishing Corporation httpwwwhindawicom

Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

SensorsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chemical EngineeringInternational Journal of Antennas and

Propagation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Navigation and Observation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

DistributedSensor Networks

International Journal of

International Journal of Antennas and Propagation 11

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

50

(a) Horizontal polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

5

(b) Vertical polarization

minus90

minus80

minus70

minus60

minus50minus40

minus30minus20minus10

0 10 2030

4050

6070

8090

MeasuredSimulated

0minus5

minus10

minus15

minus20

minus25

minus30

minus35Relat

ive a

mpl

itude

(dB)

50

(c) Diagonal polarization

Figure 19 The polarization tracking patterns measured at 125 GHz with beam scanned to 50∘

Table 2 The measured data at 125 GHz for the developed small phased array prototype

Desired scan angle (deg) 0∘ 20∘ 40∘ 50∘

H V D H V D H V D H V DPeak gain (dBi)

Simulated 187 187 187 184 185 185 177 179 179 169 175 173Measured 183 185 182 179 177 180 172 174 175 161 163 162

Aperture efficiency () 87 91 85 79 76 81 68 71 72 52 55 53SLL (dB) minus133 minus118 minus113 minus123 minus133 minus106 minus113 minus84 minus60 minus79 minus88 minus74Half-power beam width (deg) 222∘ 213∘ 216∘ 219∘ 237 222∘ 243∘ 252∘ 243∘ 264∘ 249∘ 255∘

Beam pointing error (deg) 0 minus12∘ 3∘ minus14∘ 22∘ minus14∘ minus34∘ minus34∘ minus16∘ minus41∘ minus59∘ 13∘

5 Conclusion

We propose a compact polarization tracking active phasedarray for Ku-band satellite communicationThe phased arraywith the height of 55mm is suited to be used in the applicationstrictly limiting the profile of the antenna Based on thesimulated single radiating element a small 7 times 7 array modelwas established with the simulation tool CST MicrowaveStudio The outermost 24 elements are connected to 50Ωpassive loads which contributes to the 5 times 5 active array Thewhole array was simulated and the effects of mutual couplingon the impedance of the ports can be analyzed Based onthe dimensional parameters of the isolated antenna elementthe parameters were adjusted via numerous simulations Thefinal design with mutual coupling considered had loweractive reflection coefficient of minus15 dB with beam pointed tothe boresight of the array When the array operates in thestates of horizontal vertical and diagonal polarization thesimulated active reflection coefficients versus the scan anglefor central element are plotted Furthermore we propose a

compact LTCC-based polarization trackingmodule based ona vertical transition from planar waveguide to stripline Inthe frequency range from 1225GHz to 1275GHz a smallpolarization tracking active phased array prototypewas fabri-cated and its polarization can be configured electronically viathe proposed modules The measured polarization trackingpatterns for horizontal vertical and diagonal polarization aregiven It can be found from the measurement that the beamcan be steered up to 50∘ in the elevation and the peak gain ismore than 160 dBiThe aperture efficiency of more than 50can be obtained The experiment validates the availability ofthe array design with mutual coupling considered

References

[1] S Yamamoto S Nuimura T Mizuno and Y Inasawa ldquoA Kuband small reflector antenna using backfire primary radiator forsatellite communication system on board vesselrdquo in Proceedingsof the International Symposium on Antennas and Propagation(ISAP rsquo12) pp 1273ndash1276 Nagoya Japan October 2012

12 International Journal of Antennas and Propagation

[2] J Thornton A White and G Long ldquoMulti-beam scanninglens antenna for satellite communications to trainsrdquoMicrowaveJournal vol 52 no 8 pp 56ndash70 2009

[3] A RWeily andNNikolic ldquoDual-polarized planar feed for low-profile hemispherical Luneburg lens antennasrdquo IEEE Transac-tions on Antennas and Propagation vol 60 no 1 pp 402ndash4072012

[4] S H Son and U H Park ldquoSidelobe reduction of low-profilearray antenna using a genetic algorithmrdquo ETRI Journal vol 29no 1 pp 95ndash98 2007

[5] PMousaviM Fakharzadeh S H Jamali et al ldquoA low-cost ultralow profile phased array system for mobile satellite receptionusing zero-knowledge beamforming algorithmrdquo IEEE Transac-tions on Antennas and Propagation vol 56 no 12 pp 3667ndash3679 2008

[6] S Vaccaro F Tiezzi M F Rua and C D G De Oro ldquoKu-BandLow-Profile Rx-only and Tx-Rx antennas for mobile satellitecommunicationsrdquo in Proceedings of the 4th IEEE InternationalSymposium on Phased Array Systems and Technology (Array rsquo10)pp 536ndash542 Waltham Mass USA October 2010

[7] R V Gatti L Marcaccioli E Sbarra and R SorrentinoldquoFlat array antennas for Ku-band mobile satellite terminalsrdquoInternational Journal of Antennas and Propagation vol 2009Article ID 836074 5 pages 2009

[8] C O Adler A D Monk D N Rasmussen and M J TaylorldquoTwo-way airborne broadband communications using phasedarray antennasrdquo in Proceedings of the IEEE Aerospace Confer-ence vol 2 pp 925ndash922 March 2003

[9] S Hasegawa T Yasuzumi O Hashimoto and Y KazamaldquoPolarization tracking phased array antenna with cross dipoleantenna-measured resultsrdquo in Proceedings of the IEEE Inter-national Symposium on Antennas and Propagation TorontoCanada July 2010

[10] J Zhou W Shi W B Dou and Y Shen ldquoHigh integratedmicrowave architecture using LTCC-SIP technology in activephased array antenna applicationsrdquo Frequenz vol 66 pp 177ndash182 2012

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

RoboticsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Active and Passive Electronic Components

Control Scienceand Engineering

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

RotatingMachinery

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Submit your manuscripts athttpwwwhindawicom

VLSI Design

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Shock and Vibration

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Civil EngineeringAdvances in

Acoustics and VibrationAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Electrical and Computer Engineering

Journal of

Advances inOptoElectronics

Hindawi Publishing Corporation httpwwwhindawicom

Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

SensorsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chemical EngineeringInternational Journal of Antennas and

Propagation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Navigation and Observation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

DistributedSensor Networks

International Journal of

12 International Journal of Antennas and Propagation

[2] J Thornton A White and G Long ldquoMulti-beam scanninglens antenna for satellite communications to trainsrdquoMicrowaveJournal vol 52 no 8 pp 56ndash70 2009

[3] A RWeily andNNikolic ldquoDual-polarized planar feed for low-profile hemispherical Luneburg lens antennasrdquo IEEE Transac-tions on Antennas and Propagation vol 60 no 1 pp 402ndash4072012

[4] S H Son and U H Park ldquoSidelobe reduction of low-profilearray antenna using a genetic algorithmrdquo ETRI Journal vol 29no 1 pp 95ndash98 2007

[5] PMousaviM Fakharzadeh S H Jamali et al ldquoA low-cost ultralow profile phased array system for mobile satellite receptionusing zero-knowledge beamforming algorithmrdquo IEEE Transac-tions on Antennas and Propagation vol 56 no 12 pp 3667ndash3679 2008

[6] S Vaccaro F Tiezzi M F Rua and C D G De Oro ldquoKu-BandLow-Profile Rx-only and Tx-Rx antennas for mobile satellitecommunicationsrdquo in Proceedings of the 4th IEEE InternationalSymposium on Phased Array Systems and Technology (Array rsquo10)pp 536ndash542 Waltham Mass USA October 2010

[7] R V Gatti L Marcaccioli E Sbarra and R SorrentinoldquoFlat array antennas for Ku-band mobile satellite terminalsrdquoInternational Journal of Antennas and Propagation vol 2009Article ID 836074 5 pages 2009

[8] C O Adler A D Monk D N Rasmussen and M J TaylorldquoTwo-way airborne broadband communications using phasedarray antennasrdquo in Proceedings of the IEEE Aerospace Confer-ence vol 2 pp 925ndash922 March 2003

[9] S Hasegawa T Yasuzumi O Hashimoto and Y KazamaldquoPolarization tracking phased array antenna with cross dipoleantenna-measured resultsrdquo in Proceedings of the IEEE Inter-national Symposium on Antennas and Propagation TorontoCanada July 2010

[10] J Zhou W Shi W B Dou and Y Shen ldquoHigh integratedmicrowave architecture using LTCC-SIP technology in activephased array antenna applicationsrdquo Frequenz vol 66 pp 177ndash182 2012

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

RoboticsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Active and Passive Electronic Components

Control Scienceand Engineering

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

RotatingMachinery

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Submit your manuscripts athttpwwwhindawicom

VLSI Design

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Shock and Vibration

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Civil EngineeringAdvances in

Acoustics and VibrationAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Electrical and Computer Engineering

Journal of

Advances inOptoElectronics

Hindawi Publishing Corporation httpwwwhindawicom

Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

SensorsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chemical EngineeringInternational Journal of Antennas and

Propagation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Navigation and Observation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

DistributedSensor Networks

International Journal of

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

RoboticsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Active and Passive Electronic Components

Control Scienceand Engineering

Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

International Journal of

RotatingMachinery

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Submit your manuscripts athttpwwwhindawicom

VLSI Design

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Shock and Vibration

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Civil EngineeringAdvances in

Acoustics and VibrationAdvances in

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Electrical and Computer Engineering

Journal of

Advances inOptoElectronics

Hindawi Publishing Corporation httpwwwhindawicom

Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

SensorsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Chemical EngineeringInternational Journal of Antennas and

Propagation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

Navigation and Observation

International Journal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014

DistributedSensor Networks

International Journal of