Research Article Compact Planar Sparse Array Antenna …downloads.hindawi.com/journals/ijap/2015/806981.pdf · Research Article Compact Planar Sparse Array Antenna with Optimum Element

Research ArticleCompact Planar Sparse Array Antenna with Optimum ElementDimensions for SATCOM Ground Terminals

Junqi Lu12 and Yongxin Guo2

1School of Electronic Science and Engineering National University of Defense Technology Deya Road Changsha 410073 China2Department of Electrical and Computer Engineering National University of Singapore Singapore 117576

Correspondence should be addressed to Junqi Lu junqilukegmailcom

Received 19 August 2015 Accepted 3 December 2015

Academic Editor Jaume Anguera

Copyright copy 2015 J Lu and Y Guo This is an open access article distributed under the Creative Commons Attribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited

A novel antenna array architecture for low-cost and compact SATCOM mobile terminal is presented Based on equal-amplitudeaperiodic phased array with fewer active chain numbers it possesses advantages including lower weight less cost and higher powerefficiency compared to conventional periodic phased arrays It is implemented with printed patch antenna so that it guaranteescompactness The elements position and dimensions are jointly designed with an effective sparse array synthesis strategy thattakes actual patch antenna design constraint into consideration to obtain a maximum array aperture efficiency Executable andpractical approach for variable dimension patch antenna designing including defect substrate element and small scale array isintroduced and utilized to implement proposed sparse array Full-wave simulation results demonstrate the advantages of proposedarray antenna as well as the effectiveness of corresponding design approach

1 Introduction

For the land and maritime satellite communication (SAT-COM) terminals especially the Communication-On-The-Move (COTM) application the beam steering capability isa compulsory requirement to the antenna Both mechanicaland electrical beam steering technologies could be utilized toaccomplish this task but the latter has significant advantagesincluding quicker response lower profile and light weightAmong all the electrical beam steering antennas phasedarray antennas possess ultimate performance in terms ofbeam steering accuracy beam shaping capability and func-tion flexibility However the extremely high cost of phasedarray restricted it from being widely applied in civilianand commercial areas The cost of phased array is mostlybrought in by the large number of active RF components(eg phase shifters amplifiers) within itThough some classicmethods for reducing the number of active components inphased array have been developed such as subarraying theseapproaches are not applicable when wide angle beam steeringis required

Sparse array with fewer active control numbers providesan alternative way to reduce the cost of phased array It

has been demonstrated that an array with fewer radiatingelements located aperiodically on the array aperture couldexhibit comparable performance in terms of pattern shapingand side lobe suppression [1ndash3] Another advantage of sparsearray is that it is possible to use an equal-amplitude excitationinstead of conventional tapering excitation In this caseall the power amplifiers in the active chains could operateat their best efficiency point thus maximizing the DC-RFefficiency [4]The design methods of sparse array were firstlyintroduced in the 1960s [5 6] and got rapidly developed inrecent years with the aid of advance optimization algorithms[7 8] and high efficiency EM computing techniques A seriesof problems on the design of a sparse array have beenthoroughly discussed in the past few years including patternsynthesis [9 10] mutual coupling effects consideration andtackling [11 12] and novel sparsethinned strategies [13ndash15]However as intrinsic drawbacks the gain of sparse arraywould decrease roughly proportional to the reduction ofnumber of radiating elements [16] and a strict sidelobe level(SLL) requirement is hard to be accomplished for sparse arrayespecially in scanning situation [17] These shortcomingsmight explain the reason why sparse array antenna has neverbeen put into practical use in SATCOM terminals till now

Hindawi Publishing CorporationInternational Journal of Antennas and PropagationVolume 2015 Article ID 806981 11 pageshttpdxdoiorg1011552015806981

2 International Journal of Antennas and Propagation

except for few demonstration systems developed by ESAwhich might still be far from real application [18]

The poor aperture efficiency is a fundamental limitationof sparse array if identical elements are used especially whenlow SLL is required [19] To counteract these limitations thesize of each element could be introduced as an additionaldesign parameter for sparse array besides the position andexcitation of elements [14 19 20]The design principle strat-egy and radiating performance of sparse array with jointlyoptimized element positions and dimensions have been thor-oughly discussed in [19 21] Compared to traditional equal-amplitude excitation sparse array with isotropic or identicalelements it was shown in [19] that a sparse array withelements which have different aperture dimensions exhibitsmuch better aperture efficiency and 21 dB gain increas-ing could be obtained An accurate and complete designapproach was also introduced in this literature Howeverthere are still some problems left to be discussed and tackledFirstly the proposedmethod in [19 21] is based on the utiliza-tion of ideal ldquomax efficiencyrdquo elements which are not actuallyachievable and therefore degraded its effectiveness Secondlythe indicated research background in [19] is the antenna forspace platforms especially the GEO SATCOM satellite forwhich only a limited scanning angle is required In this casethe proposed method is demonstrated with a sparse arrayconsisting of horn antennas whose aperture dimensions varyfrom 2120582 to 34120582 It could be inferred that a wide angle beamsteering with low SLL is hardly to be accomplished with thisarray configuration We also found in [19] that this configu-ration makes it easier to conduct synthesis procedure com-pared to those more typical phased arrays whose minimumelement aperture is usually not larger than 07120582 On theother hand the using of horn antennas prevented the imple-mentation of a low profile antenna array Although it wasmentioned in the literature that other kinds of antennas suchas printed patches could be used as array element solutionsno further discussions were provided on how to modify thearray synthesis method according to the actual radiatingproperties of those antennas rather than the ideal ldquomaxefficiencyrdquo model

In this paper a high efficiency sparse array synthesismethod is introduced and utilized to design a sparse arraywith patch antenna A simple but effective defect substratetechnology is utilized to implement patch antennas withdifferent aperture dimensions while working in the same fre-quency With proposed synthesis method and diverse patchantenna elements an annular sparse array is designed andhas its performance evaluated and compared with those oftraditional periodic array and sparse array

This paper is organized as follows In Section 2 the highaperture efficiency annular sparse array synthesis principleis briefly introduced In Section 3 the designing of a highefficiency annular sparse array with dimension variablesquare aperture antenna elements is conducted The designof an annular sparse array based on different kinds of patchantenna elements is carried out in Section 4 In Section 5 theperformance of proposed sparse array is analyzed and someconclusion derived

2 High Aperture Efficiency Sparse ArraySynthesis Principles

It has been proven that the relationship between the exci-tation and the radiation pattern of two particular antennaarrays could be formulated as follows [19]

int

infin

0

1

(1198960119906)2

10038161003816100381610038161198650 (119906) minus 119865119906 (119906)1003816100381610038161003816

2

119906 119889119906

= (2120587

1198960

)int

infin

0

1

1205882

10038161003816100381610038161198680 (120588) minus 119868119906 (120588)1003816100381610038161003816

2

120588 119889120588

1198960=2120587

1205820

119906 = sin (120579)

(1)

where1198650(119906) and 119868

0(119906) are the reference pattern and excitation

cumulative function 119865119906(119906) and 119868

119906(119906) are the pattern which

intends to imitate the reference and its excitation cumulativefunction

It is therefore logical to conduct the sparse array synthesiswith the strategy of imitating the excitation cumulative func-tion of the reference target The common density taperingmethod for sparse array synthesis is a specific case of thisstrategy On the other hand instead of calculating the com-plete radiation pattern of particular excitation for assessingthe array synthesis results one can take the cumulativefunction of the excitation as the evaluating object Comparedto the calculation of radiation pattern which might betime-consuming to some extent the handling of cumulativefunction is much more effective

The synthesis principle could be graphically interpretedand shown in Figure 1 By utilizing a joint position anddimension adjustment on the excitation the cumulativefunction could be closer to the reference function Thereforeaccording to (1) the corresponding radiation pattern couldbe more similar to what is expected Detailed introductionon this issue has been given in [19 21]

3 Synthesis Method of Annular Sparse Arraywith Patch Antenna

For the COTM terminal antennas there is no specificpreferred direction in the whole upper hemisphere spaceTherefore a circle could be viewed as themost suitable outlineof the proposed phased array Meanwhile for the sake ofpattern symmetries and implementation simplicity annularconfiguration of the elements is preferable to rectangular ortriangular grids configurations Therefore the design will befocused on annular arrays

For the purpose of reducing the profile and cost ofproposed sparse array compact radiating element should beutilized instead of bulky ones such as horn or waveguidePrinted patch is a maturely developed antenna with advan-tages including low profile and low fabrication cost It hasbeen widely used in COTM terminal antennas in recentyears [18 22] thus demonstrating its feasibility in SATCOMapplication For these reasons printed patch is chosen as theradiating element for the proposed sparse phased array

International Journal of Antennas and Propagation 3

Exci

tatio

n am

plitu

de

Cum

ulat

ive f

unct

ion

Exci

tatio

n am

plitu

de

Cum

ulat

ive f

unct

ion

Periodic amplitudeTapering

Tapering

Array case

Aperiodic density

Sparse array case

Exci

tatio

n am

plitu

de

Cum

ulat

ive f

unct

ion

Aperiodic density anddimension tapering

Sparse array case

D20Array aperture

D20Array aperture

D20Array aperture

D20Array aperture

D20Array aperture

D20Array aperture

Figure 1 High aperture efficiency sparse array synthesis principle

In order to apply the proposed element position anddimension joint synthesis approach a prerequisite is todetermine the aperture dimension of patch antenna In thispaper the dimension is defined as the edge length of a virtualsquare radiating aperture This virtual square could also beviewed as the effective aperture of patch antenna and couldbe obtained from the gain with the following equation inwhich 119863patch denotes the aperture dimension 119860eff denotesthe virtual square or effective aperture and 119866patch and 120582

represent the gain and operating wavelength of the patchantenna

119863patch = radic119860eff =radic119866patch sdot 120582

2

4120587

(2)

The patch antenna could be roughly viewed as a squareaperture and the aperture dimension is to be determined by(2) To synthesize a high efficiency annular sparse array with


annular arrayElement position of Taylor tapering

(m)

02

0150

1

0050

minus0

05

minus0

1

minus0

15

minus02

minus02

minus015

minus01

minus005

0

005

01

015

02

(m)

annular arrayElement position of conventional sparse

(m)

02

0150

1

0050

minus0

05

minus0

1

minus0

15

minus02

minus02

minus015

minus01

minus005

0

005

01

015

02

(m)

annular arrayElement position of novel sparse

(m)

02

0150

1

0050

minus0

05

minus0

1

minus0

15

minus02

minus02

minus015

minus01

minus005

0

005

01

015

02

(m)

02

0150

1

0050

minus0

05

minus0

1

minus0

15

minus02

Ring diameter (m)

002040608

1

exci

tatio

nM

agni

tude

of

02

0150

1

0050

minus0

05

minus0

1

minus0

15

minus02

Ring diameter (m)

002040608

1

exci

tatio

nM

agni

tude

of

02

0150

1

0050

minus0

05

minus0

1

minus0

15

minus02

Ring diameter (m)

002040608

1

exci

tatio

nM

agni

tude

of

minus60

minus40

minus20 0 20 40 60 80

minus80

minus80

minus60

minus40

minus20

020406080

0minus10minus20minus30minus40minus50minus60minus70minus80minus90minus100minus110

minus60

minus40

minus20 0 20 40 60 80

minus80

minus80

minus60

minus40

minus20

020406080

0minus10minus20

minus30

minus40

minus50

minus60

minus70

minus80

40200 60 80

minus40

minus60

minus20

minus80

0minus10minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100minus80

minus60

minus40

minus20

020406080

Figure 2 Synthesis results of annular periodic array (left column) conventional sparse array (middle column) and proposed high efficiencysparse array (right column) The array elements distribution (upper row) excitation distribution (middle row) and radiation pattern (lowerrow) are illustrated

square aperture elements the first step is to obtain the widthof each coaxial ring area of the proposed annular sparse arrayaccording to themethod thoroughly introduced in [19] Oncethe width of each ring is obtained then the dimension of thesquare aperture elements to be populated in the ring areascould be determined as a portion close to but not reaching1 for example 08 or 09 of the ring width Each ring areashould be populated by as many elements as possible withoutoverlap All square apertures should be located on the circlewhich represents the geometric center of the ring area

A set of illustrative synthesis results are shown in Figures2 and 3 and Table 1 A minus25 dB SLL requirement is achievedby a periodic annular array a conventional density taperingarray and the proposed high efficiency sparse array It couldbe noticed in Figure 2 that although having only about30 of the number of elements the proposed sparse arrayexhibits an almost identical aperture efficiency compared to

Table 1 Syntheiss results of three kinds of annual arrays

Periodicarray

Conventionalsparse array

Highefficiencysparse array

Number of elements 452 270 169Directivity (dBi) 3398 3190 3362SLL (dB) minus259 minus2495 minus252Aperture efficiency 8664 5364 7956

periodic array This performance is much better than thatof a conventional annular sparse array with only one kindof element The SLL requirement is well fulfilled with allthe three arrays yet the performance of proposed array isobviously better than that of traditional sparse array as shownin Figure 3


Novel sparse array dir = 3052dBConventional sparse array dir = 2889 dBPeriodic annular array dir = 3098dB

10 20 30 40 50 60 70 80 900120579 (deg)

minus50

minus40

minus30

minus20

minus10

0

Nor

mal

ized

dire

ctiv

ity (d

B)

5 10 15 20 250minus40minus35minus30minus25minus20minus15minus10minus5

0

Figure 3 Pattern synthesis results of minus25 dB SLL pattern

4 Design Results of a Compact Annular SparseArray with Patch Antenna

Based on the array synthesis results introduced above ahigh efficiency compact annular sparse array is designedThedesign work consists of (1) designing of printed patch anten-nas having different aperture dimensions and (2) designingof annular sparse array with those patch antennas Thedemonstrating frequency is chosen at 1425GHz which is atypical value of practical SATCOM uplink band

41 Design of Patch Antennas Having Different AperturesAccording to the array synthesis results the required aperturedimensions vary from 06120582 to 161120582 Two strategies areutilized to achieve this requirement that is simple defectsubstrate patch and 2 times 2 arrays

411 Defect Substrate Patches for Aperture Dimensions NotLarger Than 09120582 Unlike real aperture antennas such asthe horn antenna introduced in [19 23] whose physicalaperture could be easily defined and continually adjustableprinted patch antennas exhibit a much more strict constrainton the dimension of the antenna aperture In general thesize of patch antenna 119863patch should be about half of theeffective wavelength 120582eff which is mostly determined bythe effective dielectric constant 120576eff thickness of substrate119905sub and a modification factor 120581structure which represents thestructure effects (eg multilayer or inhomogeneous substrateand superstrate)

119863patch asymp120582eff2=1205820120576eff2 120576eff sim 120576sub 119905sub 120581structure (3)

In order to adjust the effective aperture of printed patchantenna without affecting the operating band one executablesolution is to modify the effective dielectric constant of thesubstrate Several approaches could be used to achieve this

Lower substrate Rogers R03006

Upper substrateRogers RT5880

W_patchW_defect

T_01

T_02Patch

Feeding probeGround plane

Defectsubstrate

cavity

Figure 4 Sectional view of defect substrate patch antenna

purpose while the defect substrate technology would be anoptimal choice By removing part of the substrate betweenpatch and ground plane the effective dielectric constantcould be variedwithin a particular range specifically (1) higheffective dielectric constant if no substrate is removed (2)moderate effective dielectric constant if part of substrate isremoved (defect) and (3) low effective dielectric constant ifalmost all substrate is removed The technology is shown inprinciple in Figure 4

The proposed defect substrate patch antenna consists offive parts (1) the printed radiating patch (2) the uppersubstrate to supporting patches (3) the lower substratepatch in which defect cavity is constructed to adjust theaperture dimension of antenna (4) differential feeding probeto provide a low cross-polarization radiation and (5) groundplane The upper substrate should be much thinner thanthe lower substrate to maximize the adjusting efficiency ofeffective dielectric constant via defect substrate technologyThe two-layer substrate structure makes it very easy toproceed substrate removal work For a joint consideration ofelectrical and mechanic performance as well as fabricationfeasibility the material of lower substrate is chosen as RogersR0306 (120576

119903= 615) and the thickness T 01 is 05mm the

material of upper substrate is chosen as Rogers RT5880 (120576119903=

22) and thickness T 02 is 0127mmThe primary parameter in the design of defect substrate

patch antenna is the defect factor K defect which could beeasily defined as the ratio between the width of subdefectedcavity W defect and radiating patch W patch The value ofK defect ranges from 0 to a particular positive numberTheoretically the aperture of patches could be modified con-tinually by changing K defect However the patch dimensionwould become very sensitive to the changing of the size ofdefect substrate cavity when the value of K defect is gettingclose to 1 This nonlinear response will bring in unnecessarydifficulties in fabrication In this case only three types ofdefect substrate patch antenna are designed (1) complete


V-polar feeding

H-polar feeding

Decoupler

Radiating

Array spacing

Arrayspacing

patch times 4

divider times 6

Figure 5 Pairwise mirrored element array

Table 2 Design parameters of simple defect substrate patchantenna

Element 1 Element 2 Element 3119882 patch (mm) 395 69 90119882 defect (mm) 0 70 120Aperture size (mm) 128 152 183Directivity 462 652 946

Table 3 Design parameters of proposed element array

Element 4 Element 5 Element 6Components Element 1 Element 2 Element 3Array spacing (mm) 100 120 140Aperture size (mm) 259 288 338Directivity 1257 2104 3248

substrate ones with 128mm aperture size (element 1) (2)partially defective substrate ones with 152mm aperture size(element 2) and (3) fully defective substrate ones with183mm aperture size (element 3) (Table 2)

412 Small Arrays for Aperture Dimensions LargerThan 09120582The maximum available aperture dimension of a simpledefect substrate patch is about 09120582 For larger aperturesrequirement small scale arrays could be adopted For theconsideration of symmetries of radiating patterns and themaximum aperture size constraint only a 2 times 2 arrayconfiguration is suitable for this purpose

In order to guarantee a low cross-polarization level apairwise mirrored elements configuration which was intro-duced in [24] is utilized The array fabrication and feedingnetwork is shown in Figure 5

For the sake of fabrication simplicity three types of arraysare designed with the aperture dimensions (1) 259mm (2)288mm and (3) 338mm (Table 3)Three different elements

Element 1Element 2Element 3


0

5

10

15

20

25

30

35

E-fi

eld

(vm

)

10 20 30 40 50 60 70 80 900120579 (deg)

Figure 6 E-field pattern of designed elements



1350 1375 1400 1425 1450 1475 1500 15251325Frequency (GHz)

minus30

minus25

minus20

minus15

minus10

minus5

0

Retu

rn lo

ss (d

B)

Figure 7 Return loss of designed elements

designed in the last section are used in the design of thesethree arrays

The performance and design results of elements 1ndash6are illustrated in Figures 6 and 7 It could be verified thatthe E-field amplitude in the boresight direction of each ele-ment is roughly proportional to its aperture dimension andall elementsrsquo operating frequency locates around 1425GHzalthough with different aperture dimensions

42 Design of High Efficiency Sparse Array with Patch AntennaElements Based on the array synthesis and element designresults obtained an entire high efficiency sparse array ismodeled and simulated using CST MW Studio The 1st and2nd rings of elements near the center are implemented with


9 annual rings of elements with 6 types of elements

Upper substrate supportingpatch elements

Lower substrate defected forvariable aperture elements

Ground plane

Integrated view

Exploded view

Array dimension = 362mm

Total thickness = 07mm

Thickness = 0035mm

Thickness = 05mmRogers RO3006 120576r = 615

Thickness = 0127mmRogers RT5880 120576r = 220

Thickness = 0035mm

Figure 8 Detailed structure of proposed sparse array

Table 4 Simulation results of three types of arrays

Periodicarray


High efficiencysparse array

Number of elements 452 270 169Directivity (dBi) 333 311 332SLL (dB) minus265 minus216 minus242Aperture diameter 362mm 362mm 362mmAperture efficiency 7326 4415 7160

element 1 the 3rd and 4th rings are implemented withelement 2 the 5th and 6th rings are implemented withelement 3The 7th 8th and 9th rings are implemented witharray elements 4 5 and 6 respectively The total numberof independently excited elements is 143

The array overall structure is the combination of all theelements and could be divided into 4 parts just like eachelement (1) the radiating patches (2) the upper substratewhich ismainly for supporting patches above (3) the defectedlower substrate to implement aperture adjustment and (4)the ground plane The total thickness is only 07mm or0033120582

0(the feeding net layer excluded) Figure 8 shows the

detail of the array model It is clear that a common PCBtechnology could be easily utilized to fabricate this arraywithout any complicated procedure

The characteristics and performance are summarized inTable 4 The most noticeable point is that the SLL of sparsearrays is not achieved Our research shows that it is due tothe complicated mutual coupling effects

5 Technical Results and Discussion

Since all the elementsrsquo excitation amplitudes are identicalin the proposed sparse array all power amplifiers could beoperating in their best efficiency point thus maximizing theoverall DC-RF efficiency Taking a typical power amplifierDC-RF efficiency curve as shown in Figure 10 as an example[4] it could be noticed that the lower the amplifier output thelower the DC-RF efficiency

The equivalent isotropically radiated power (EIRP)which is the product of antenna gain and input RF power iscalculated and assessed among three types of annular arraysand the results are summarized in Figure 11 The values ofperiodic array are taken as reference and values of othersare proportionally drawn in the figure The most noticeablepoints in the figure are that (1)withmuch fewer elements theproposed sparse array exhibits an almost identical directivityas the periodic array and (2) by using density tapering insteadof amplitude tapering theDC-RF efficiency is doubledAs forthe EIRP value it is logical to obtain a significant increase

Beam scanning capability is a key performance require-ment of COTM terminal antennaThe scanning performanceof proposed sparse array is simulated and assessed someresults are illustrated in Figure 12

The maximum grating-lobe free scanning angle is about55 degrees with respect to the boresight direction A minus6 dBgain beam could be achieved at about 35-degree scanningangle and minus10 dB gain beam obtained at about 45 degreesCompared to the periodic annular array of which there isno grating-lobe in the entire upper hemisphere the minus6 andminus10 dB scanning angles are 55 and 73 degrees respectivelyFor the conventional annular sparse array consisting of


minus30

minus20

minus10

0

10

20

30

40

(dBi

)

Farfield directivity Abs(Φ = 90)

Frequency = 1425

Main lobe magnitude = 333dBiMain lobe direction = 1800 degAngular width (3dB) = 38degSide lobe level = minus265dB

Farfield (f = 1425) [SimExPeriodic_array_v02_24

6040200 80 90

minus40

minus60

minus80

minus20

minus90

120579 (deg)

(a)

minus30

minus20

minus10

0

10

20

30

40

(dBi

)

Frequency = 1425

Main lobe magnitude = 311dBiMain lobe direction = 1800 degAngular width (3dB) = 38degSide lobe level = minus216 dB

Farfield (f = 1425) [SimExSparse_array_v02_18_to_24_rounds-expend 105tsv]

minus80

minus60

minus40

minus20 0 20 40 60 80 90

minus90

120579 (deg)

(b)

minus30

minus20

minus10

0

10

20

30

40

(dBi

)

Frequency = 1425


Farfield (f = 1425) [SimExexp_v02_excitationstsv]

6040200 80 90

minus40

minus60

minus80

minus20

minus90

120579 (deg)

(c)

Figure 9 Simulation model and results of three arrays (1) periodic annular array (upper) (2) conventional sparse array (middle) and (3)high efficiency sparse array (lower)


Efficiency of RF amplifier

0

005

01

015

02

025

03

035

04

DC-

RF co

nver

sion

effici

ency

minus9 minus8 minus7 minus6 minus5 minus4 minus3 minus2 minus1minus10 0RF output backoff (dB)

Figure 10 Power amplifier DC-RF conversion efficiency

Number of Directivity RF outputelements (dBi) from PAs

EIRP

RF performance comparison

Periodic arrayConventional sparse array

High efficiency sparse array

005

115

225

452270

169

333 311 332

10 209 209 10 126 204

Figure 11 RF performance comparison

identical radiating elements there is also no grating-lobe inthe whole visible area and the minus6 dB beam scanning anglesare 58 degrees minus10 dB beam scanning angle almost reachesthe horizontal direction

Apparently for the proposed sparse array the beamscanning performance is not optimal and that might limitits global application in COTM terminals This problemcould be inferred from the intrinsic drawback of densitytapering array [5] Nevertheless considering the advantageof the proposed sparse array in DC-RF efficiency and EIRPlevel it is still a promising solution for COTM ground andmaritime terminals if the deploying area is restricted in thelow latitude and tropical regions where the zenith angle ofGEO communication satellite will not be greater than 30 or40 degrees especially for those steadymoving platforms suchas trains or ships or vehicles running in urban area or onexpressways

As shown in Figure 13 the gain of beam steering to 30degrees with respect to zenith direction is 26 dBi comparableto that of conventional sparse array Though 29 dB lowerthan the gain of the beam of periodic array in the samescanning situation the final EIRP value would be predictedto be almost the same since the gap could be filled up by a3 dB DC-RF efficiency gain It could also be noticed that theside lobe near main beam is always kept in a low level as thebeam scanningmdasha favorable characteristic of SATCOM

6 Conclusion

An effective design strategy of high efficiency sparse arrayantenna has been introduced Both elementsrsquo position anddimension are utilized as synthesis parameters and optimizedsimultaneously Both analytical and full-wave simulationresults demonstrate the effectiveness and accuracy of theintroduced method (Figures 2 and 9 and Tables 1 and 4) Theproposed printed patch antenna based sparse array is verycompact and could be easily fabricated at a low cost Theaperture efficiency of proposed sparse array is significantlybetter than those of conventional sparse array with identicalelement and is comparable to that of periodic array

The scanning performance of proposed array is limitedto a relatively small range This is an extremely unfavorablefeature for COTM application However the problem is notsevere in low latitude regions Considering the advantageof significant reduction on the active components numberwhich reduces cost and power consumption remarkably thedrawbacks of proposed antenna array are possible to becompensated

The mutual coupling might bring in unfavorable effectson the performance of sparse arrayThis is an urgent problemthat needs to be studied and tackled on the topic of sparsearray researches


120579 = 15∘ 120579 = 30∘

120579 = 45∘ 120579 = 60∘

0

minus10

minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100

minus110

0

minus10

minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100

minus110

0

minus10

minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100

minus110

0

minus10

minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100

minus110

minus80

minus60

minus40

minus20

0

20

40

60

80

minus80

minus60

minus40

minus20

0

20

40

60

80

minus80

minus60

minus40

minus20

0

20

40

60

80

minus80

minus60

minus40

minus20

0

20

40

60

80

minus40 minus20minus60minus80 8040 60200minus60 minus40 minus20 0 20 40 60minus80 80

minus60 40 60minus80 200minus40 80minus20 minus60 4020 60minus80 0minus40 80minus20

Figure 12 Scanning beam pattern of proposed sparse array

Boresight10-degree scanning

20-degree scanning30-degree scanning

minus20

minus10

0

10

20

30

40

Dire

ctiv

ity (d

Bi)

minus50 minus40 minus30 minus20 minus10minus60 10 20 30 40 50 600Scanning angle (deg)

Figure 13 Scanning beam of proposed sparse array

Conflict of Interests

The authors declare that there is no conflict of interestsregarding the publication of this paper

References

[1] F Hodjat and S A Hovanessian ldquoNonuniformly spaced linearand planar array antennas for sidelobe reductionrdquo IEEE Trans-actions on Antennas and Propagation vol 26 no 2 pp 198ndash2041978

[2] B P Kumar and G R Branner ldquoDesign of unequally spacedarrays for performance improvementrdquo IEEE Transactions onAntennas and Propagation vol 47 no 3 pp 511ndash523 1999

[3] R M Leahy and B D Jeffs ldquoOn the design of maximally sparsebeamforming arraysrdquo IEEE Transactions on Antennas andPropagation vol 39 no 8 pp 1178ndash1187 1991

[4] G Toso P Angeletti and C Mangenot ldquoA comparison ofdensity and amplitude tapering for transmit active arraysrdquo inProceedings of the 3rd European Conference on Antennas and


Propagation (EuCAP rsquo09) pp 840ndash843 Berlin GermanyMarch2009

[5] A Maffett ldquoArray factors with nonuniform spacing parameterrdquoIRETransactions onAntennas and Propagation vol 10 no 2 pp131ndash136 1962

[6] A Ishimaru ldquoTheory of unequally-spaced arraysrdquo IRE Transac-tions on Antennas and Propagation vol 10 no 6 pp 691ndash7021962

[7] L Zhang Y-C Jiao B Chen and H Li ldquoOrthogonal geneticalgorithm for planar thinned array designsrdquo International Jour-nal of Antennas and Propagation vol 2012 Article ID 319037 7pages 2012

[8] S K Goudos K Siakavara T Samaras E E Vafiadis and J NSahalos ldquoSparse linear array synthesis withmultiple constraintsusing differential evolution with strategy adaptationrdquo IEEEAntennas andWireless Propagation Letters vol 10 pp 670ndash6732011

[9] D Caratelli and M C Vigano ldquoAnalytical synthesis techniquefor linear uniform-amplitude sparse arraysrdquo Radio Science vol46 no 4 pp 1ndash6 2011

[10] M C Vigano G Toso and D Caratelli ldquoA hybrid determinis-ticmetaheuristic synthesis technique for non-uniformly spacedlinear printed antenna arraysrdquo in Proceedings of the 7th Euro-pean Conference on Antennas and Propagation pp 3650ndash3653April 2013

[11] C Bencivenni M V Ivashina R Maaskant and J WettergrenldquoDesign of maximally sparse antenna arrays in the presenceof mutual couplingrdquo IEEE Antennas and Wireless PropagationLetters vol 14 pp 159ndash162 2015

[12] S-W Qu C H Chan M-Y Xia and Z Nie ldquoHigh-efficiencyperiodic sparse microstrip array based on mutual couplingrdquoIEEE Transactions on Antennas and Propagation vol 61 no 4pp 1963ndash1970 2013

[13] M C Vigano G Toso G Caille C Mangenot and I ELager ldquoSunflower array antenna with adjustable density taperrdquoInternational Journal of Antennas and Propagation vol 2009Article ID 624035 10 pages 2009

[14] OMBucci T Isernia A FMorabito S Perna andD PincheraldquoDensity and element-size tapering for the design of arrays witha reduced number of control points and high efficiencyrdquo in Pro-ceedings of the 4th European Conference on Antennas and Pro-pagation pp 1ndash4 April 2010

[15] M-Y Zheng K-S Chen H-G Wu and X-P Liu ldquoSparseplanar array synthesis using matrix enhancement and matrixpencilrdquo International Journal of Antennas and Propagation vol2013 Article ID 147097 7 pages 2013

[16] R Willey ldquoSpace tapaering of linear and planar arraysrdquo IRETransactions on Antennas and Propagation vol 10 no 4 pp369ndash377 1962

[17] Y Lo and S Lee ldquoA study of space-tapered arraysrdquo IEEETransactions on Antennas and Propagation vol 14 no 1 pp 22ndash30 1966

[18] M C Vigano D L del Rio F Bongard and S Vaccaro ldquoSparsearray antenna for Ku-band mobile terminals using 1 bit phasecontrolsrdquo IEEE Transactions on Antennas and Propagation vol62 no 4 pp 1723ndash1730 2014

[19] P Angeletti G Toso and G Ruggerini ldquoArray antennas withjointly optimized elements positions and dimensions Part IIPlanar circular arraysrdquo IEEE Transactions on Antennas andPropagation vol 62 no 4 pp 1627ndash1639 2014

[20] A Catalani L Russo O M Bucci T Isernia and G TosoldquoSparse arrays for satellite communications from optimaldesign to realizationrdquo in Proceedings of the 32nd ESA AntennaWorkshop on Antennas for Space Applications pp 5ndash8 Noord-wijk The Netherlands October 2010

[21] P Angeletti andG Toso ldquoArray antennas with jointly optimizedelements positions and dimensions part I linear arraysrdquo IEEETransactions on Antennas and Propagation vol 62 no 4 part 1pp 1619ndash1626 2014

[22] L Baggen S Vaccaro D Llorens del Rio J Padilla and RT Sanchez ldquoA compact phased array for satcom applicationsrdquoin Proceedings of the IEEE International Symposium on PhasedArray SystemsampTechnology pp 232ndash239WalthamMass USAOctober 2013

[23] G Ruggerini ldquoA compact circular horn with high efficiencyrdquoin Proceedings of the 4th European Conference on Antennas andPropagation (EuCAP rsquo10) pp 1ndash3 IEEE Barcelona Spain April2010

[24] J Granholm and K Woelders ldquoDual polarization stackedmicrostrip patch antenna array with very low cross-polarizationrdquo IEEE Transactions on Antennas and Propagationvol 49 no 10 pp 1393ndash1402 2001

International Journal of

AerospaceEngineeringHindawi Publishing Corporationhttpwwwhindawicom Volume 2014

RoboticsJournal of

Hindawi Publishing Corporationhttpwwwhindawicom Volume 2014


Active and Passive Electronic Components

Control Scienceand Engineering

Journal of



RotatingMachinery


Hindawi Publishing Corporation httpwwwhindawicom

Journal ofEngineeringVolume 2014

Submit your manuscripts athttpwwwhindawicom

VLSI Design



Shock and Vibration


Civil EngineeringAdvances in

Acoustics and VibrationAdvances in



Electrical and Computer Engineering

Journal of

Advances inOptoElectronics


Volume 2014

The Scientific World JournalHindawi Publishing Corporation httpwwwhindawicom Volume 2014

SensorsJournal of


Modelling amp Simulation in EngineeringHindawi Publishing Corporation httpwwwhindawicom Volume 2014


Chemical EngineeringInternational Journal of Antennas and

Propagation




Navigation and Observation



DistributedSensor Networks



except for few demonstration systems developed by ESAwhich might still be far from real application [18]

The poor aperture efficiency is a fundamental limitationof sparse array if identical elements are used especially whenlow SLL is required [19] To counteract these limitations thesize of each element could be introduced as an additionaldesign parameter for sparse array besides the position andexcitation of elements [14 19 20]The design principle strat-egy and radiating performance of sparse array with jointlyoptimized element positions and dimensions have been thor-oughly discussed in [19 21] Compared to traditional equal-amplitude excitation sparse array with isotropic or identicalelements it was shown in [19] that a sparse array withelements which have different aperture dimensions exhibitsmuch better aperture efficiency and 21 dB gain increas-ing could be obtained An accurate and complete designapproach was also introduced in this literature Howeverthere are still some problems left to be discussed and tackledFirstly the proposedmethod in [19 21] is based on the utiliza-tion of ideal ldquomax efficiencyrdquo elements which are not actuallyachievable and therefore degraded its effectiveness Secondlythe indicated research background in [19] is the antenna forspace platforms especially the GEO SATCOM satellite forwhich only a limited scanning angle is required In this casethe proposed method is demonstrated with a sparse arrayconsisting of horn antennas whose aperture dimensions varyfrom 2120582 to 34120582 It could be inferred that a wide angle beamsteering with low SLL is hardly to be accomplished with thisarray configuration We also found in [19] that this configu-ration makes it easier to conduct synthesis procedure com-pared to those more typical phased arrays whose minimumelement aperture is usually not larger than 07120582 On theother hand the using of horn antennas prevented the imple-mentation of a low profile antenna array Although it wasmentioned in the literature that other kinds of antennas suchas printed patches could be used as array element solutionsno further discussions were provided on how to modify thearray synthesis method according to the actual radiatingproperties of those antennas rather than the ideal ldquomaxefficiencyrdquo model

In this paper a high efficiency sparse array synthesismethod is introduced and utilized to design a sparse arraywith patch antenna A simple but effective defect substratetechnology is utilized to implement patch antennas withdifferent aperture dimensions while working in the same fre-quency With proposed synthesis method and diverse patchantenna elements an annular sparse array is designed andhas its performance evaluated and compared with those oftraditional periodic array and sparse array

This paper is organized as follows In Section 2 the highaperture efficiency annular sparse array synthesis principleis briefly introduced In Section 3 the designing of a highefficiency annular sparse array with dimension variablesquare aperture antenna elements is conducted The designof an annular sparse array based on different kinds of patchantenna elements is carried out in Section 4 In Section 5 theperformance of proposed sparse array is analyzed and someconclusion derived

2 High Aperture Efficiency Sparse ArraySynthesis Principles

It has been proven that the relationship between the exci-tation and the radiation pattern of two particular antennaarrays could be formulated as follows [19]

int

infin

0

1

(1198960119906)2

10038161003816100381610038161198650 (119906) minus 119865119906 (119906)1003816100381610038161003816

2

119906 119889119906

= (2120587

1198960

)int

infin

0

1

1205882

10038161003816100381610038161198680 (120588) minus 119868119906 (120588)1003816100381610038161003816

2

120588 119889120588

1198960=2120587

1205820

119906 = sin (120579)

(1)

where1198650(119906) and 119868

0(119906) are the reference pattern and excitation

cumulative function 119865119906(119906) and 119868

119906(119906) are the pattern which

intends to imitate the reference and its excitation cumulativefunction

It is therefore logical to conduct the sparse array synthesiswith the strategy of imitating the excitation cumulative func-tion of the reference target The common density taperingmethod for sparse array synthesis is a specific case of thisstrategy On the other hand instead of calculating the com-plete radiation pattern of particular excitation for assessingthe array synthesis results one can take the cumulativefunction of the excitation as the evaluating object Comparedto the calculation of radiation pattern which might betime-consuming to some extent the handling of cumulativefunction is much more effective

The synthesis principle could be graphically interpretedand shown in Figure 1 By utilizing a joint position anddimension adjustment on the excitation the cumulativefunction could be closer to the reference function Thereforeaccording to (1) the corresponding radiation pattern couldbe more similar to what is expected Detailed introductionon this issue has been given in [19 21]

3 Synthesis Method of Annular Sparse Arraywith Patch Antenna

For the COTM terminal antennas there is no specificpreferred direction in the whole upper hemisphere spaceTherefore a circle could be viewed as themost suitable outlineof the proposed phased array Meanwhile for the sake ofpattern symmetries and implementation simplicity annularconfiguration of the elements is preferable to rectangular ortriangular grids configurations Therefore the design will befocused on annular arrays

For the purpose of reducing the profile and cost ofproposed sparse array compact radiating element should beutilized instead of bulky ones such as horn or waveguidePrinted patch is a maturely developed antenna with advan-tages including low profile and low fabrication cost It hasbeen widely used in COTM terminal antennas in recentyears [18 22] thus demonstrating its feasibility in SATCOMapplication For these reasons printed patch is chosen as theradiating element for the proposed sparse phased array


Exci

tatio

n am

plitu

de

Cum

ulat

ive f

unct

ion

Exci

tatio

n am

plitu

de

Cum

ulat

ive f

unct

ion


Tapering

Array case

Aperiodic density

Sparse array case

Exci

tatio

n am

plitu

de

Cum

ulat

ive f

unct

ion


Sparse array case

D20Array aperture

D20Array aperture

D20Array aperture

D20Array aperture

D20Array aperture

D20Array aperture





2

4120587

(2)




(m)

02

0150

1

0050

minus0

05

minus0

1

minus0

15

minus02

minus02

minus015

minus01

minus005

0

005

01

015

02

(m)


(m)

02

0150

1

0050

minus0

05

minus0

1

minus0

15

minus02

minus02

minus015

minus01

minus005

0

005

01

015

02

(m)


(m)

02

0150

1

0050

minus0

05

minus0

1

minus0

15

minus02

minus02

minus015

minus01

minus005

0

005

01

015

02

(m)

02

0150

1

0050

minus0

05

minus0

1

minus0

15

minus02

Ring diameter (m)

002040608

1

exci

tatio

nM

agni

tude

of

02

0150

1

0050

minus0

05

minus0

1

minus0

15

minus02

Ring diameter (m)

002040608

1

exci

tatio

nM

agni

tude

of

02

0150

1

0050

minus0

05

minus0

1

minus0

15

minus02

Ring diameter (m)

002040608

1

exci

tatio

nM

agni

tude

of

minus60

minus40

minus20 0 20 40 60 80

minus80

minus80

minus60

minus40

minus20

020406080


minus60

minus40

minus20 0 20 40 60 80

minus80

minus80

minus60

minus40

minus20

020406080

0minus10minus20

minus30

minus40

minus50

minus60

minus70

minus80

40200 60 80

minus40

minus60

minus20

minus80

0minus10minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100minus80

minus60

minus40

minus20

020406080





Periodicarray







10 20 30 40 50 60 70 80 900120579 (deg)

minus50

minus40

minus30

minus20

minus10

0

Nor

mal

ized

dire

ctiv

ity (d

B)


0










W_patchW_defect

T_01

T_02Patch


Defectsubstrate

cavity









V-polar feeding

H-polar feeding

Decoupler

Radiating

Array spacing

Arrayspacing

patch times 4

divider times 6












0

5

10

15

20

25

30

35

E-fi

eld

(vm

)

10 20 30 40 50 60 70 80 900120579 (deg)




1350 1375 1400 1425 1450 1475 1500 15251325Frequency (GHz)

minus30

minus25

minus20

minus15

minus10

minus5

0

Retu

rn lo

ss (d

B)









Ground plane

Integrated view

Exploded view



Thickness = 0035mm



Thickness = 0035mm



Periodicarray















minus30

minus20

minus10

0

10

20

30

40

(dBi

)


Frequency = 1425



6040200 80 90

minus40

minus60

minus80

minus20

minus90

120579 (deg)

(a)

minus30

minus20

minus10

0

10

20

30

40

(dBi

)

Frequency = 1425



minus80

minus60

minus40

minus20 0 20 40 60 80 90

minus90

120579 (deg)

(b)

minus30

minus20

minus10

0

10

20

30

40

(dBi

)

Frequency = 1425



6040200 80 90

minus40

minus60

minus80

minus20

minus90

120579 (deg)

(c)




0

005

01

015

02

025

03

035

04

DC-

RF co

nver

sion

effici

ency




EIRP




005

115

225

452270

169

333 311 332

10 209 209 10 126 204





6 Conclusion





120579 = 15∘ 120579 = 30∘

120579 = 45∘ 120579 = 60∘

0

minus10

minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100

minus110

0

minus10

minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100

minus110

0

minus10

minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100

minus110

0

minus10

minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100

minus110

minus80

minus60

minus40

minus20

0

20

40

60

80

minus80

minus60

minus40

minus20

0

20

40

60

80

minus80

minus60

minus40

minus20

0

20

40

60

80

minus80

minus60

minus40

minus20

0

20

40

60

80






minus20

minus10

0

10

20

30

40

Dire

ctiv

ity (d

Bi)





References





























RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










Exci

tatio

n am

plitu

de

Cum

ulat

ive f

unct

ion

Exci

tatio

n am

plitu

de

Cum

ulat

ive f

unct

ion


Tapering

Array case

Aperiodic density

Sparse array case

Exci

tatio

n am

plitu

de

Cum

ulat

ive f

unct

ion


Sparse array case

D20Array aperture

D20Array aperture

D20Array aperture

D20Array aperture

D20Array aperture

D20Array aperture





2

4120587

(2)




(m)

02

0150

1

0050

minus0

05

minus0

1

minus0

15

minus02

minus02

minus015

minus01

minus005

0

005

01

015

02

(m)


(m)

02

0150

1

0050

minus0

05

minus0

1

minus0

15

minus02

minus02

minus015

minus01

minus005

0

005

01

015

02

(m)


(m)

02

0150

1

0050

minus0

05

minus0

1

minus0

15

minus02

minus02

minus015

minus01

minus005

0

005

01

015

02

(m)

02

0150

1

0050

minus0

05

minus0

1

minus0

15

minus02

Ring diameter (m)

002040608

1

exci

tatio

nM

agni

tude

of

02

0150

1

0050

minus0

05

minus0

1

minus0

15

minus02

Ring diameter (m)

002040608

1

exci

tatio

nM

agni

tude

of

02

0150

1

0050

minus0

05

minus0

1

minus0

15

minus02

Ring diameter (m)

002040608

1

exci

tatio

nM

agni

tude

of

minus60

minus40

minus20 0 20 40 60 80

minus80

minus80

minus60

minus40

minus20

020406080


minus60

minus40

minus20 0 20 40 60 80

minus80

minus80

minus60

minus40

minus20

020406080

0minus10minus20

minus30

minus40

minus50

minus60

minus70

minus80

40200 60 80

minus40

minus60

minus20

minus80

0minus10minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100minus80

minus60

minus40

minus20

020406080





Periodicarray







10 20 30 40 50 60 70 80 900120579 (deg)

minus50

minus40

minus30

minus20

minus10

0

Nor

mal

ized

dire

ctiv

ity (d

B)


0










W_patchW_defect

T_01

T_02Patch


Defectsubstrate

cavity









V-polar feeding

H-polar feeding

Decoupler

Radiating

Array spacing

Arrayspacing

patch times 4

divider times 6












0

5

10

15

20

25

30

35

E-fi

eld

(vm

)

10 20 30 40 50 60 70 80 900120579 (deg)




1350 1375 1400 1425 1450 1475 1500 15251325Frequency (GHz)

minus30

minus25

minus20

minus15

minus10

minus5

0

Retu

rn lo

ss (d

B)









Ground plane

Integrated view

Exploded view



Thickness = 0035mm



Thickness = 0035mm



Periodicarray















minus30

minus20

minus10

0

10

20

30

40

(dBi

)


Frequency = 1425



6040200 80 90

minus40

minus60

minus80

minus20

minus90

120579 (deg)

(a)

minus30

minus20

minus10

0

10

20

30

40

(dBi

)

Frequency = 1425



minus80

minus60

minus40

minus20 0 20 40 60 80 90

minus90

120579 (deg)

(b)

minus30

minus20

minus10

0

10

20

30

40

(dBi

)

Frequency = 1425



6040200 80 90

minus40

minus60

minus80

minus20

minus90

120579 (deg)

(c)




0

005

01

015

02

025

03

035

04

DC-

RF co

nver

sion

effici

ency




EIRP




005

115

225

452270

169

333 311 332

10 209 209 10 126 204





6 Conclusion





120579 = 15∘ 120579 = 30∘

120579 = 45∘ 120579 = 60∘

0

minus10

minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100

minus110

0

minus10

minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100

minus110

0

minus10

minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100

minus110

0

minus10

minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100

minus110

minus80

minus60

minus40

minus20

0

20

40

60

80

minus80

minus60

minus40

minus20

0

20

40

60

80

minus80

minus60

minus40

minus20

0

20

40

60

80

minus80

minus60

minus40

minus20

0

20

40

60

80






minus20

minus10

0

10

20

30

40

Dire

ctiv

ity (d

Bi)





References





























RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation











(m)

02

0150

1

0050

minus0

05

minus0

1

minus0

15

minus02

minus02

minus015

minus01

minus005

0

005

01

015

02

(m)


(m)

02

0150

1

0050

minus0

05

minus0

1

minus0

15

minus02

minus02

minus015

minus01

minus005

0

005

01

015

02

(m)


(m)

02

0150

1

0050

minus0

05

minus0

1

minus0

15

minus02

minus02

minus015

minus01

minus005

0

005

01

015

02

(m)

02

0150

1

0050

minus0

05

minus0

1

minus0

15

minus02

Ring diameter (m)

002040608

1

exci

tatio

nM

agni

tude

of

02

0150

1

0050

minus0

05

minus0

1

minus0

15

minus02

Ring diameter (m)

002040608

1

exci

tatio

nM

agni

tude

of

02

0150

1

0050

minus0

05

minus0

1

minus0

15

minus02

Ring diameter (m)

002040608

1

exci

tatio

nM

agni

tude

of

minus60

minus40

minus20 0 20 40 60 80

minus80

minus80

minus60

minus40

minus20

020406080


minus60

minus40

minus20 0 20 40 60 80

minus80

minus80

minus60

minus40

minus20

020406080

0minus10minus20

minus30

minus40

minus50

minus60

minus70

minus80

40200 60 80

minus40

minus60

minus20

minus80

0minus10minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100minus80

minus60

minus40

minus20

020406080





Periodicarray







10 20 30 40 50 60 70 80 900120579 (deg)

minus50

minus40

minus30

minus20

minus10

0

Nor

mal

ized

dire

ctiv

ity (d

B)


0










W_patchW_defect

T_01

T_02Patch


Defectsubstrate

cavity









V-polar feeding

H-polar feeding

Decoupler

Radiating

Array spacing

Arrayspacing

patch times 4

divider times 6












0

5

10

15

20

25

30

35

E-fi

eld

(vm

)

10 20 30 40 50 60 70 80 900120579 (deg)




1350 1375 1400 1425 1450 1475 1500 15251325Frequency (GHz)

minus30

minus25

minus20

minus15

minus10

minus5

0

Retu

rn lo

ss (d

B)









Ground plane

Integrated view

Exploded view



Thickness = 0035mm



Thickness = 0035mm



Periodicarray















minus30

minus20

minus10

0

10

20

30

40

(dBi

)


Frequency = 1425



6040200 80 90

minus40

minus60

minus80

minus20

minus90

120579 (deg)

(a)

minus30

minus20

minus10

0

10

20

30

40

(dBi

)

Frequency = 1425



minus80

minus60

minus40

minus20 0 20 40 60 80 90

minus90

120579 (deg)

(b)

minus30

minus20

minus10

0

10

20

30

40

(dBi

)

Frequency = 1425



6040200 80 90

minus40

minus60

minus80

minus20

minus90

120579 (deg)

(c)




0

005

01

015

02

025

03

035

04

DC-

RF co

nver

sion

effici

ency




EIRP




005

115

225

452270

169

333 311 332

10 209 209 10 126 204





6 Conclusion





120579 = 15∘ 120579 = 30∘

120579 = 45∘ 120579 = 60∘

0

minus10

minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100

minus110

0

minus10

minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100

minus110

0

minus10

minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100

minus110

0

minus10

minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100

minus110

minus80

minus60

minus40

minus20

0

20

40

60

80

minus80

minus60

minus40

minus20

0

20

40

60

80

minus80

minus60

minus40

minus20

0

20

40

60

80

minus80

minus60

minus40

minus20

0

20

40

60

80






minus20

minus10

0

10

20

30

40

Dire

ctiv

ity (d

Bi)





References





























RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation











10 20 30 40 50 60 70 80 900120579 (deg)

minus50

minus40

minus30

minus20

minus10

0

Nor

mal

ized

dire

ctiv

ity (d

B)


0










W_patchW_defect

T_01

T_02Patch


Defectsubstrate

cavity









V-polar feeding

H-polar feeding

Decoupler

Radiating

Array spacing

Arrayspacing

patch times 4

divider times 6












0

5

10

15

20

25

30

35

E-fi

eld

(vm

)

10 20 30 40 50 60 70 80 900120579 (deg)




1350 1375 1400 1425 1450 1475 1500 15251325Frequency (GHz)

minus30

minus25

minus20

minus15

minus10

minus5

0

Retu

rn lo

ss (d

B)









Ground plane

Integrated view

Exploded view



Thickness = 0035mm



Thickness = 0035mm



Periodicarray















minus30

minus20

minus10

0

10

20

30

40

(dBi

)


Frequency = 1425



6040200 80 90

minus40

minus60

minus80

minus20

minus90

120579 (deg)

(a)

minus30

minus20

minus10

0

10

20

30

40

(dBi

)

Frequency = 1425



minus80

minus60

minus40

minus20 0 20 40 60 80 90

minus90

120579 (deg)

(b)

minus30

minus20

minus10

0

10

20

30

40

(dBi

)

Frequency = 1425



6040200 80 90

minus40

minus60

minus80

minus20

minus90

120579 (deg)

(c)




0

005

01

015

02

025

03

035

04

DC-

RF co

nver

sion

effici

ency




EIRP




005

115

225

452270

169

333 311 332

10 209 209 10 126 204





6 Conclusion





120579 = 15∘ 120579 = 30∘

120579 = 45∘ 120579 = 60∘

0

minus10

minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100

minus110

0

minus10

minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100

minus110

0

minus10

minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100

minus110

0

minus10

minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100

minus110

minus80

minus60

minus40

minus20

0

20

40

60

80

minus80

minus60

minus40

minus20

0

20

40

60

80

minus80

minus60

minus40

minus20

0

20

40

60

80

minus80

minus60

minus40

minus20

0

20

40

60

80






minus20

minus10

0

10

20

30

40

Dire

ctiv

ity (d

Bi)





References





























RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










V-polar feeding

H-polar feeding

Decoupler

Radiating

Array spacing

Arrayspacing

patch times 4

divider times 6












0

5

10

15

20

25

30

35

E-fi

eld

(vm

)

10 20 30 40 50 60 70 80 900120579 (deg)




1350 1375 1400 1425 1450 1475 1500 15251325Frequency (GHz)

minus30

minus25

minus20

minus15

minus10

minus5

0

Retu

rn lo

ss (d

B)









Ground plane

Integrated view

Exploded view



Thickness = 0035mm



Thickness = 0035mm



Periodicarray















minus30

minus20

minus10

0

10

20

30

40

(dBi

)


Frequency = 1425



6040200 80 90

minus40

minus60

minus80

minus20

minus90

120579 (deg)

(a)

minus30

minus20

minus10

0

10

20

30

40

(dBi

)

Frequency = 1425



minus80

minus60

minus40

minus20 0 20 40 60 80 90

minus90

120579 (deg)

(b)

minus30

minus20

minus10

0

10

20

30

40

(dBi

)

Frequency = 1425



6040200 80 90

minus40

minus60

minus80

minus20

minus90

120579 (deg)

(c)




0

005

01

015

02

025

03

035

04

DC-

RF co

nver

sion

effici

ency




EIRP




005

115

225

452270

169

333 311 332

10 209 209 10 126 204





6 Conclusion





120579 = 15∘ 120579 = 30∘

120579 = 45∘ 120579 = 60∘

0

minus10

minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100

minus110

0

minus10

minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100

minus110

0

minus10

minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100

minus110

0

minus10

minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100

minus110

minus80

minus60

minus40

minus20

0

20

40

60

80

minus80

minus60

minus40

minus20

0

20

40

60

80

minus80

minus60

minus40

minus20

0

20

40

60

80

minus80

minus60

minus40

minus20

0

20

40

60

80






minus20

minus10

0

10

20

30

40

Dire

ctiv

ity (d

Bi)





References





























RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation













Ground plane

Integrated view

Exploded view



Thickness = 0035mm



Thickness = 0035mm



Periodicarray















minus30

minus20

minus10

0

10

20

30

40

(dBi

)


Frequency = 1425



6040200 80 90

minus40

minus60

minus80

minus20

minus90

120579 (deg)

(a)

minus30

minus20

minus10

0

10

20

30

40

(dBi

)

Frequency = 1425



minus80

minus60

minus40

minus20 0 20 40 60 80 90

minus90

120579 (deg)

(b)

minus30

minus20

minus10

0

10

20

30

40

(dBi

)

Frequency = 1425



6040200 80 90

minus40

minus60

minus80

minus20

minus90

120579 (deg)

(c)




0

005

01

015

02

025

03

035

04

DC-

RF co

nver

sion

effici

ency




EIRP




005

115

225

452270

169

333 311 332

10 209 209 10 126 204





6 Conclusion





120579 = 15∘ 120579 = 30∘

120579 = 45∘ 120579 = 60∘

0

minus10

minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100

minus110

0

minus10

minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100

minus110

0

minus10

minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100

minus110

0

minus10

minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100

minus110

minus80

minus60

minus40

minus20

0

20

40

60

80

minus80

minus60

minus40

minus20

0

20

40

60

80

minus80

minus60

minus40

minus20

0

20

40

60

80

minus80

minus60

minus40

minus20

0

20

40

60

80






minus20

minus10

0

10

20

30

40

Dire

ctiv

ity (d

Bi)





References





























RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










minus30

minus20

minus10

0

10

20

30

40

(dBi

)


Frequency = 1425



6040200 80 90

minus40

minus60

minus80

minus20

minus90

120579 (deg)

(a)

minus30

minus20

minus10

0

10

20

30

40

(dBi

)

Frequency = 1425



minus80

minus60

minus40

minus20 0 20 40 60 80 90

minus90

120579 (deg)

(b)

minus30

minus20

minus10

0

10

20

30

40

(dBi

)

Frequency = 1425



6040200 80 90

minus40

minus60

minus80

minus20

minus90

120579 (deg)

(c)




0

005

01

015

02

025

03

035

04

DC-

RF co

nver

sion

effici

ency




EIRP




005

115

225

452270

169

333 311 332

10 209 209 10 126 204





6 Conclusion





120579 = 15∘ 120579 = 30∘

120579 = 45∘ 120579 = 60∘

0

minus10

minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100

minus110

0

minus10

minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100

minus110

0

minus10

minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100

minus110

0

minus10

minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100

minus110

minus80

minus60

minus40

minus20

0

20

40

60

80

minus80

minus60

minus40

minus20

0

20

40

60

80

minus80

minus60

minus40

minus20

0

20

40

60

80

minus80

minus60

minus40

minus20

0

20

40

60

80






minus20

minus10

0

10

20

30

40

Dire

ctiv

ity (d

Bi)





References





























RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation











0

005

01

015

02

025

03

035

04

DC-

RF co

nver

sion

effici

ency




EIRP




005

115

225

452270

169

333 311 332

10 209 209 10 126 204





6 Conclusion





120579 = 15∘ 120579 = 30∘

120579 = 45∘ 120579 = 60∘

0

minus10

minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100

minus110

0

minus10

minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100

minus110

0

minus10

minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100

minus110

0

minus10

minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100

minus110

minus80

minus60

minus40

minus20

0

20

40

60

80

minus80

minus60

minus40

minus20

0

20

40

60

80

minus80

minus60

minus40

minus20

0

20

40

60

80

minus80

minus60

minus40

minus20

0

20

40

60

80






minus20

minus10

0

10

20

30

40

Dire

ctiv

ity (d

Bi)





References





























RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation










120579 = 15∘ 120579 = 30∘

120579 = 45∘ 120579 = 60∘

0

minus10

minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100

minus110

0

minus10

minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100

minus110

0

minus10

minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100

minus110

0

minus10

minus20

minus30

minus40

minus50

minus60

minus70

minus80

minus90

minus100

minus110

minus80

minus60

minus40

minus20

0

20

40

60

80

minus80

minus60

minus40

minus20

0

20

40

60

80

minus80

minus60

minus40

minus20

0

20

40

60

80

minus80

minus60

minus40

minus20

0

20

40

60

80






minus20

minus10

0

10

20

30

40

Dire

ctiv

ity (d

Bi)





References





























RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation

































RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation











RoboticsJournal of





Journal of



RotatingMachinery





VLSI Design



Shock and Vibration







Journal of



Volume 2014


SensorsJournal of





Propagation









Documents

Research Article Compact Planar Sparse Array Antenna …downloads.hindawi.com/journals/ijap/2015/806981.pdf · Research Article Compact Planar Sparse Array Antenna with Optimum Element