1. L/C Dual-Band Dual-Polarized Shared Aperture Array
COMP 901 / ITEC 810 Final Report
Author: Zhu SUN ( )
Supervisor: Prof. Karu Esselle
Date: 13/06/2012

2. Outline Introduction Theoretical Analysis
L/C-DBDP Half Perforated Unit Cell
L/C-DBDP Overlapped Unit Cell
L/C-DBDP Half Perforated Full Array
Conclusion

3. Introduction --Background
Improve payload efficiency in space- and air-borne cases; ease the deployment and maintainance
Fig.2 Space- & Air-Borne case
Fig.1 Base station antenna

4. Introduction --Literature Review
Fig.4 Overlapped Structure [2]
Fig.3 Perforated Patch [1]
Fig.5 Interleaved Structure [3]
L. L. Shafai, W. A. Chamma, M. Barakat, P. C. Strickland, and G. Séguin, “Dual-band dual-polarized perforated microstrip antennas for SAR applications”, IEEE Trans. Antennas Propagat., vol. 48, no. 1, pp.58-66, Jan
M. Moghaddam, et al, “A Dual Polarized UHF/VHF Honeycomb Stacked-Patch Feed Array for a Large-Aperture Space-borne Radar Antenna”, Aerospace Conf. 2007, pp.1-10
X. Qu, S.S. Zhong, Y.M. Zhang and W. Wang, “Design of an S/X dual-band dual-polarised microstrip antenna array for SAR applications”, IET Microw. Antennas Propag., vol.1, no.2, pp. 513–517, 2007.

5. Theoretical Analysis --expression explanation (I)
Fig.6 Field Distribution & Equivalent M-current

6. Theoretical Analysis --expression explanation (II)
Perforation has similar effect as shorten radiation edge
From Transmission Line Model, equivalent circuit parameters [4] can be written as: ;
Q factor can be expressed as:
, where
Conclusion: bandwidth scales with
radiation edge width
4. H.Pues, etal, “Accurate transmission-line model for the rectangular microstrip antenna”, Microwaves, Optics and Antennas, IEE Proceedings H, vol.131, no.6, pp

7. Theoretical Analysis --simulation result (I)
Non-Perforated
Half-Perforated
Fully-Perforated
Fig.7 Comparison of three structures

8. Theoretical Analysis --simulation result (II)
Bandwidth decreases with the increase of perforations
Fig.8 Simulated bandwidth of three structures

9. L/C-DBDP Half Perforated Unit Cell --Configuration
Reduce Perforation Number
Lower Profile
Trade off in Bandwidth
Moderate Complexity
Fig.9 Configuration of
“half-perforated” unit cell

10. L/C-DBDP Half Perforated Unit Cell --Inter-band Coupling
Fig.10 coupling from C element to L element
Fig.11 coupling from L element to C element

11. L/C-DBDP Half Perforated Unit Cell --Fabrication & Measurement
Top View
Bottom View
Fig.13 Antenna Under Measurement
Side View
Fig.12 Fabricated Half-Perforated Unit Cell

12. L/C-DBDP Half Perforated Unit Cell --Measurement Results (I)
VSWR
VSWR
VSWR
Isolation
Isolation
Fig.14 L band Measured Port Parameters
Fig.14 L band Measured Port Parameters
Fig.14 L band Measured Port Parameters

13. L/C-DBDP Half Perforated Unit Cell --Measurement Results (II)
Fig.15 L band Measured Radiation Pattern

14. L/C-DBDP Half Perforated Unit Cell --Measurement Results (III)
VSWR
VSWR
VSWR
Isolation
Isolation
Fig.16 C band Measured Port Parameters
Fig.16 C band Measured Port Parameters
Fig.16 C band Measured Port Parameters

15. L/C-DBDP Half Perforated Unit Cell --Measurement Results (IV)
Fig.17 C band Measured Radiation Pattern

16. L/C-DBDP Overlapped Unit Cell --Configuration (I)
Fig.18 Configuration of “overlapped” unit cell

17. L/C-DBDP Overlapped Unit Cell --Configuration (II)
Fig.19 Vertical transfer method

18. L/C-DBDP Overlapped Unit Cell --Fabrication & Measurement
Fig.20 Fabricated Overlapped Unit Cell

19. L/C-DBDP Overlapped Unit Cell --Measurement Results (I)
S Parameters
S Parameters
Radiation Pattern
Radiation Pattern
Fig.21 L band Measured Results

20. L/C-DBDP Overlapped Unit Cell --Measurement Results (II)
S Parameters
Radiation Pattern
Fig.22 C band Measured Results

21. L/C-DBDP Unit Cell --Measured Data Conclusion
Table I. Measured results of L/C DBDP unit cell
specification
Overlapped Structure
Half Perforated Structure
L band (1.25GHz)
C band (5.3GHz)
Bandwidth (MHz)
219
790
166
802
Bandwidth (%)
17.6 15 13
15.8
polarization
Dual-linear polar
Isolation (dB) 17 19 21
X polarization (dB)
-23
-25
-30
Gain (dB)
9.9
13.4
9.7
10.3
1st SLL (dB) --
-15(E) / -21(H)
-5(E) / -13(H)

22. L/C-DBDP Half Perforated Full Array --Sidelobe Level Calibration
Perspective View
Side View
Simulated Radiation Pattern
Fig.23 Raised Ground & SLL Calibration

23. L/C-DBDP Half Perforated Full Array --Configuration
Perspective View
Top View
Fig.24 Configuration of Half Perforated Full Array

24. L/C-DBDP Half Perforated Full Array --Simulated Results
L band
C band
Fig.25 Simulated S-Parameters of full array

25. L/C-DBDP Half Perforated Full Array --Layout (I)
Aluminum Plate
Upper Surface
SMA via hole
Metal Perturbation
with via hole
L band cavity
Aluminum Plate
downside
SMA connector

26. L/C-DBDP Half Perforated Full Array --Layout (II)
L driven patch &
C driven patch
C Parasitic Patch

27. L/C-DBDP Half Perforated Full Array --Layout (III)
L Perforated Parasitic Patch

28. Conclusion
Theoretically explain relationship between bandwidth and perforation
Design and fabricate a L/C “half perforated” unit cell
Design and fabricate a L/C “overlapped” unit cell
An L/C “half perforated” full array is designed and under fabrication

29. Q & A
Thanks !