Upload
dokhanh
View
213
Download
0
Embed Size (px)
Citation preview
Design of Double-Layer Transmitarray Antenna based on 3D Printing Technology
Ahmed H. Abdelrahman and Hao Xin
Department of Electrical and Computer Engineering, University of Arizona, USA
Transmitarray antennas have received considerable attention in the area of high gain antennas. They
combine the advantages of the microstrip antenna arrays and the lens antennas, leading to the light weight
and low profile designs. A transmitarray antenna consists of multiple layers of planar array elements and
an illuminating feed source. The transmission phase of each element is designed independently to convert
the spherical phase front from the feed source into a planar phase front and focus the radiation beam with
a high gain. However, a full transmission phase range of 360° cannot be achieved by a single layer of
array elements, and therefore a design of multiple layers is required.
3D printing technology has recently attracted a growing interest in the microwave field as a novel
manufacturing technique. This technology allows the rapid prototyping of 3D arbitrary structures at low
cost. The goal of this work is to decrease the number of conductor layers using the 3D printing
technology, thereby reducing the complexity and cost of designing transmitarray antennas. The design
methodology is based on using two groups of unit cells. Each unit-cell group is composed of two layers
of printed elements separated by a dielectric material. The two groups have the same dielectric thickness
but different relative permittivities, such that the transmission coefficient phase range of each unit cell
group is different from the phase range of the other group. When combining the two phase ranges, a full
transmission coefficient phase range of 360° is obtained.
A polymer-jetting 3D printing technology will be used to fabricate the proposed transmitarray aperture,
which includes a mix of two different dielectric properties. As an example, Fig. 1 presents a parametric
analysis of the two double-layer unit cells using an arbitrary conductor element. The two unit cells have
the same substrate thicknesses equal to 0.4 wavelength, but different relative dielectric permittivity equal
to 1 and 2.8, respectively. It can be noticed that a full transmission phase range of 360° is achieved with
transmission magnitude better than -2 dB. These simulations were carried out using the commercial
software ANSYS HFSS.
Keywords: Transmitarray antenna, multilayer, transmission phase range, 3D printing.
(a) (b)
Fig. 1. Transmission coefficient versus element dimensions at 10 GHz, (a) magnitude, and (b) phase.
References: [1] A. H. Abdelrahman, A. Z. Elsherbeni, and F. Yang, “Transmission phase limit of multilayer frequency selective surfaces
for transmitarray designs,” IEEE Transactions on Antennas and Propagation, vol. 62, no. 2, pp. 690-697, February 2014.
[2] M. Liang, and H. Xin, "Three-dimensionally printed/additive manufactured antennas." In Handbook of Antenna
Technologies, pp. 1-30. Springer Singapore, 2015.
9 10 11 12-5
-4
-3
-2
-1
0
Element Dimensions (mm)
|S2
1| (d
B)
r = 1
r = 2.8
9 10 11 12-180
-90
0
90
180
Element Dimensions (mm)
S
21 (
degre
es)
r = 1
r = 2.8
Forum for Electromagnetic Research Methods and Applications Technologies (FERMAT)
*This use of this work is restricted solely for academic purposes. The author of this work owns the copyright and no reproduction in any form is permitted without written permission by the author. *
Ahmed H. Abdelrahman, (S’13–M’15) received the B.S. and M.S. degrees in Electrical
Engineering, Electronics and Communications from Ain Shams University, Cairo, Egypt, in
2001 and 2010, respectively. He received the Ph.D. degree in Engineering Sciences from The
University of Mississippi, University, MS, USA, in 2014. Dr. Abdelrahman is currently a
Postdoctoral Research Associate in The Electrical and Computer Engineering Department at
The University of Arizona, Tucson, AZ, USA. His research interests include
Transmitarray/Reflectarray Antennas, Mobile Antennas, 3D Printed Antennas, and
Thermoacoustic and Millimeter-Wave Imaging.
Dr. Abdelrahman has received several prestigious awards, including the third place winner
student paper competition award at the 2013 ACES annual conference, and the honorable mention student paper
competition at the 2014 IEEE AP-S International Symposium on Antennas and Propagation. Dr. Abdelrahman also
possess over eight years of experience in Satellite Communications industry. He worked as RF Design Engineer and
Communication System Engineer in building the low earth orbit satellite Egyptsat-1.
Dr. Hao Xin, Professor of Electrical and Computer Engineering at the University of Arizona. He
is named an Arizona Engineering fellow in Aug. 2013. He also serves as the inaugural director
of the Cognitive Sensing Center of the ECE department at the University of Arizona. He joined
University of Arizona since August 2005 as an assistant professor. He was promoted to tenured
associate professor in 2009 and to full professor in 2012. From 2000 to 2003, he was a research
scientist with the Rockwell Scientific Company. He was a Sr. Principal Multidisciplinary
Engineer with Raytheon Company from 2003 to 2005. He received his PhD in Physics from
Massachusetts Institute of Technology in February 2001. He obtained his BS degree in Physics
and Mathematics from University of Massachusetts Dartmouth in May 1995.
His primary research interests are in the area of microwave / millimeter wave / THz antennas, devices, circuits and
their applications in wireless communication and sensing systems. His recent research activities have covered a
broad range of high frequency technologies, including applications of new technologies and materials in microwave
and millimeter wave circuits such as electromagnetic band gap crystals and other meta-materials, carbon nano-tubes
devices, solid state devices and circuits, active or semi-active antennas, and passive circuits. He has authored over
260 referred publications and 14 patents (13 issued and 1 pending) in the areas of microwave and millimeter-wave
technologies, random power harvesting based on ferro-fluidic nano-particles and carbon nanotube based devices. He
is a senior member of IEEE and chair of the joint chapter of IEEE AP/MTT/EMC/COMM in Tucson AZ. He is a
general co-chair of the 8th International Workshop on Antenna Technology. He also serves as an associate editor
for IEEE Antennas and Wireless Propagation Letters. [email protected] 520-626-6941
1
Ahmed H. Abdelrahman and Hao XinDept. of Electrical and Computer Engineering, University of Arizona, Tucson, AZ, USA
Design of Double-Layer Transmitarray Antenna using 3D
Printing Technology
AP-S/URSI 2016
June 26 – July 1, 2016, Fajardo, Puerto Rico
Outline
2
• Introduction
•3D Printing Technology
•Multilayer FSS Transmitarray
•Proposed Transmitarray Antenna
•Conclusion
Outline
3
• Introduction
•3D Printing Technology
•Multilayer FSS Transmitarray
•Proposed Transmitarray Antenna
•Conclusion
Transmitarray Antennas
4
Microstrip Array Antenna
https://www.cst.com/Content/Articles/a
rticle915/ArrayPhoto.png
Lens antenna
http://www.rozendalassociates.com/pro
ducts/microwave-lens-antenna/
A. H. Abdelrahman et al, “Bandwidth improvement methods of transmitarray
antennas,” IEEE Trans. Ant. Prop., vol. 63, no. 7., pp. 2946-2954, July 2015
Transmitarray Antenna Transmitarray antennas combine
the favorable features of the optic
theory and array technique.
ADVANTAGES:
Low profile and light weight.
High radiation efficiency.
Flexible radiation performance.
Transmitarray antenna consists of:
o An illuminating feed source.
o A flat transmitting surface.
Description of Transmitarray Antenna
5
Transmission coefficient of each element is
individually designed.
It converts the spherical phase to a planar phase.
Required element phase range ~ 360°
𝝍𝒊 = 𝒌(𝑹𝒊 − 𝒓𝒊. ො𝒓𝒐) + 𝝍𝟎
𝝍𝒊: Transmission phase of ith element
k: Propagation constant
Ri: Distance from the feed to ith element
𝒓𝒊: Position vector of ith element
ො𝒓𝒐: Mean-beam unit vector
𝝍𝟎: Phase constant
Transmitarray Antenna vs. Lens Antenna
6
Low profile, light weight, and
low fabrication cost
Individual element control
provides versatile functionalities
Transmitarray has a relatively
narrow bandwidth
Transmitarray AntennaLens Antenna
Transmitarray vs. Reflectarray
7
Free from source blockage
More tolerant to fabrication
errors
Transmitarray requires more
volumetric space
Transmitarray Antenna
Reflectarray Antenna
Outline
8
• Introduction
•3D Printing Technology
•Multilayer FSS Transmitarray
•Proposed Transmitarray Antenna
•Conclusion
Polymer Jetting Rapid Prototyping
9
Resolution: 42 μm*42 μm* 16 μm
Fast fabrication of polymer components
with arbitrary shapes and complexity
Fused Deposition Modeling (FDM)
10
Potentially low cost
Convenient and faster fabrication process
Printed Precision = 0.4 mm
Fabrication of Metal
11
Ultrasonic / Thermal Wire Embedding
Embedded wires during the printing processUltrasonic wire embedding system
Smallest wire diameter = 50 μm
High Conductivity
Integration with FDM
Examples of 3D Printed Components
12
Luneburg Lens
THz waveguideTHz woodpile structure THz horn antenna
W-Band Reflectarrays
Examples of 3D Printed Components
13
Patch AntennaWilkinson Power Divider
Outline
14
• Introduction
•3D Printing Technology
•Multilayer FSS Transmitarray
•Proposed Transmitarray Antenna
•Conclusion
Overview of Multilayer FSS Transmitarray
15
30
210
60
240
90
270
120
300
150
330
180 0
Single layer with a conductor element
|S
21| vs. S
21
|S21
| = -1dB
|S21
| = -3dB
S21
=0S
21=90
S21
=27
S21
=45
A. H. Abdelrahman, A. Z. Elsherbeni, and F. Yang, “Transmission phase limit of multilayer frequency
selective surfaces for transmitarray designs,” IEEE Trans. Ant. Prop., vol. 62, no. 2, pp. 690-697, Feb. 2014.
Single Conductor Layer:
Phase range = 54° for |S21| < -1dB
Phase range = 90° for |S21| < -3dB
Double Conductor Layer:
Phase range = 170° for |S21| < -1dB
Phase range = 228.5° for |S21| < -3dB
Overview of Multilayer FSS Transmitarray
16
A. H. Abdelrahman, A. Z. Elsherbeni, and F. Yang, “Transmission phase limit of multilayer frequency
selective surfaces for transmitarray designs,” IEEE Trans. Ant. Prop., vol. 62, no. 2, pp. 690-697, Feb. 2014.
Triple Layer:
Phase range = 308° for |S21| < -1dB
Phase range = 360° for |S21| < -3dB
Quad Layer:
Phase range = 360° for |S21| < -1dB
Non-Identical Double Layer
17
Non-identical Layers:
Element shapes are different.
Element dimensions are different.
Non-identical double-Layer TA:
Two degrees of freedom.
Maximum phase range when the two
layers are identical.
Outline
18
• Introduction
•3D Printing Technology
•Multilayer FSS Transmitarray
•Proposed Transmitarray Antenna
•Conclusion
εr = 2.8
εr = 1
Proposed Double Layer Unit-Cell
19
(εr = 1) (εr = 2.8)
T = 12.17 mm at 10 GHz
Two-different double-layer unit-cells.
Unit-cells are different in substrate
permittivity.
Phase range = 360° for |S21| < -2dB.
Numerical Validation (Lossless Element)
20
(εr = 2.8)(εr = 1)
P = λ/2 = 15 mm, W = 0.5 mm, S = 1.75 mm
Both layers are identical
P = λ/2
L1
L2
W
W
S
Unit-Cell: Double Square Loop
Numerical Validation (Lossless Element)
21
HFSS Simulation Results
-180 -120 -60 0 60 120 180-20
-10
0
10
20
30
(degrees)
Gain
(dB
)
xz-plane
yz-plane
Transmitarray Modeling (Lossless Elements)
22
Circular aperture at 10 GHz
317 elements (Diameter = 315 mm = 10.5 λ0).
Focal length = 16 cm (F/D = 0.51).
Gain = 25 dB, SLL = -18.6 dB, BLL = -11.9 dB.
5 10 15 20
5
10
15
20
Permittivity Distribution
(εr = 2.8 & tanδ = 0.01)
Numerical Validation (Lossy Element)
23
P = λ/2 = 15 mm, W = 0.5 mm, S = 1.75 mm
Both layers are identical
P = λ/2
L1
L2
W
W
S
Unit-Cell: Double Square Loop(εr = 1)
Transmitarray Modeling (Lossy Elements)
24
Circular aperture at 10 GHz
317 elements (Diameter = 315 mm = 10.5 λ0).
Focal length = 16 cm (F/D = 0.51).
Gain = 24.8 dB, SLL = -18.7 dB, BLL = -12.5 dB.
-180 -120 -60 0 60 120 180-20
-10
0
10
20
30
(degrees)
Gain
(dB
)
xz-plane
yz-plane 5 10 15 20
5
10
15
20
Permittivity Distribution
Proposed 3D Printed Configuration
25
3D printed
3 Neighbor Elements
(εr = 2.8 & tanδ = 0.01)
0.5
1
30
210
60
240
90
270
120
300
150
330
180 0
HFSS
Analytical
(εr = 1)
3D Printed Unit-Cell
Outline
26
• Introduction
•3D Printing Technology
•Multilayer FSS Transmitarray
•Proposed Transmitarray Antenna
•Conclusion
3D Printing Technology.
Two Different Unit-Cell Structure.
Transmitarray Antenna Modeling.
Conclusion
27-180 -120 -60 0 60 120 180
-20
-10
0
10
20
30
(degrees)
Gain
(dB
)
xz-plane
yz-plane
28
Thank You