UWB Antennas and MIMO Antenna Arrays Development for Near-Field Imaging

199 Pages·2011·6.04 MB·English

UWB Antennas and MIMO Antenna Arrays
Development for Near-Field Imaging

Yu-Che YANG

UWB Antennas and MIMO Antenna Arrays
Development for Near-Field Imaging

Proefschrift

ter verkrijging van de graad van doctor
aan de Technische Universiteit Delft,
op gezag van de Rector Magnificus prof. ir. K. C. A. M. Luyben,
voorzitter van het College voor Promoties,
in het openbaar te verdedigen op donderdag 20 oktober 2011 om 12.30 uur

door

Yu-Che YANG

elektrotechnisch ingenieur
geboren te Taipei, Taiwan
Dit proefschrift is goedgekeurd door de promotor:

Prof. DSc. A. G. Yarovoy

Samenstelling promotiecommissie:

Rector Magnificus voorzitter
Prof. DSc. A. G. Yarovoy Technische Universiteit Delft, promotor
Prof. dr. ir. A. Neto Technische Universiteit Delft
Prof. ir. F. le Chevalier Technische Universiteit Delft
Prof. dr. ir. A.B. Smolders Technische Universiteit Eindhoven
Prof. dr. J.-Y. Dauvignac Université de Nice-Sophia Antipolis
Prof. dr.-ing. habil. R. S. Thomä Technische Universität Ilmenau

This research was partly supported by FP6 project Radiotect (COOP-CT-2006-
032744)

ISBN/EAN 978-94-6186-011-8
UWB Antennas and MIMO Antenna Arrays Development for Near-field Imaging.
Dissertation at Delft University of Technology.
Copyright © 2011 by Yu-Che Yang.

All rights reserved. No parts of this publication may be reproduced or transmitted
in any form or by any means, electronic or mechanical, including photocopy,
recording, or any information storage and retrieval system, without permission in
writing from the author.
To my child,
Rozen

Table of Contents
1. Introduction .................................................................................. 1
1.1 Background of the research ............................................................ 1
1.2 State-of-the-art in UWB arrays and research motivation .............. 3
1.2.1 State-of-the art in time domain UWB imaging arrays ......... 3
1.2.2 State-of-the-art in UWB antenna element development .... 4
1.3 Research objectives ......................................................................... 5
1.4 Challenges ........................................................................................ 6
1.5 Approaches ....................................................................................... 7
1.6 Novelties and achievements ........................................................... 9
1.7 Research framework ...................................................................... 10
1.8 Thesis outline ................................................................................. 10
2. Measurement facilities and techniques ................................... 17
2.1 Introduction .................................................................................... 17
2.2 Measurement challenges ............................................................... 17
2.3 Antenna gain and radiation patterns measurement setups ....... 18
2.3.1 Anechoic chamber measurement setup .......................... 18
2.3.2 Free space measurement setup ...................................... 20
2.4 S-matrix calibration technique ...................................................... 21
2.5 Data post-processing techniques ................................................. 23
2.5.1 Three-antenna gain calculation ....................................... 23
2.5.2 Mix-mode S-parameter measurement ............................. 24
2.5.3 Time-gating technique ..................................................... 25
2.6 Conclusions .................................................................................... 27
3. Microwave UWB antenna development and analysis ............ 31
3.1 Introduction .................................................................................... 31
3.2 Novel ASP antenna design ............................................................ 32
3.2.1 Description of the antenna geometry ............................... 32
3.2.2 Antenna design approach ................................................ 32
3.2.3 Choice of substrate material and thickness ..................... 33
3.2.4 Physical analysis of the antenna behavior ....................... 33
3.2.5 Interim conclusions .......................................................... 36
3.3 Antenna performance analysis ..................................................... 38
3.3.1 Reflection coefficient analysis.......................................... 38
3.3.2 Radiation patterns analysis ............................................. 39
3.3.3 Time domain behavior analysis ....................................... 44
3.4 Antenna coupling ........................................................................... 44
3.4.1 Antenna coupling measurement setup ............................ 44
3.4.2 Antenna cross-talk analysis ............................................. 45
3.4.3 Antenna scattering coupling ............................................ 48
3.5 Conclusions .................................................................................... 49
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4. K-band LTCC differentially-fed UWB antenna analysis and
development .............................................................................. 53
4.1 Introduction ..................................................................................... 53
4.2 Antenna concepts........................................................................... 53
4.2.1 Initial antenna concepts ................................................... 53
4.2.2 K-band LTCC antenna concepts ...................................... 54
4.3 Antenna investigation and optimization ....................................... 55
4.3.1 Impact of the LTCC material to the antenna radiation ..... 56
4.3.2 Influence of the elliptical dipole axis and separation ........ 58
4.3.3 Study on the multi-stair case shield ................................. 59
4.3.4 Realization of the metal shield ......................................... 60
4.3.5 Feeding network design ................................................... 63
4.3.6 Interim conclusion ............................................................ 63
4.4 Experimental verifications ............................................................. 64
4.4.1 Antenna connectorization ................................................ 64
4.4.2 Reflection coefficient analysis .......................................... 67
4.4.3 Gain and radiation patterns analysis ................................ 69
4.4.4 Time domain analysis ...................................................... 74
4.5 Manufacturing variation analysis .................................................. 75
4.5.1 Process variation ............................................................. 75
4.5.2 Variation of the relative permittivity .................................. 76
4.5.3 Variation of the substrate height ...................................... 77
4.5.4 Interim Conclusion ........................................................... 77
4.6 Integrated LTCC antenna ............................................................... 77
4.7 Conclusions .................................................................................... 78
5. M-band differentially-fed UWB antenna analysis and
development .............................................................................. 81
5.1 Introduction ..................................................................................... 81
5.2 Antenna concept ............................................................................ 82
5.3 Antenna investigation and optimization ....................................... 83
5.4 Antenna balun and shield design .................................................. 87
5.4.1 Antenna balun design ...................................................... 87
5.4.2 Antenna shield design ..................................................... 88
5.5 Experimental verification and analysis ......................................... 91
5.5.1 Manufactured antenna ..................................................... 91
5.5.2 Antenna reflection coefficient measurement and
analysis ............................................................................ 92
5.5.3 Antenna broadside gain measurement ............................ 96
5.5.4 Antenna radiation patterns measurement ........................ 97
5.5.5 Manufacturing variations ................................................ 100
5.6 Integrated antenna design ........................................................... 100
5.7 Conclusions .................................................................................. 101
6. UWB MIMO Sparse Arrays for Near-Field Imaging ............... 103
ii
6.1 Introduction .................................................................................. 103
6.2 UWB array performance evaluation and presentation .............. 103
6.2.1 UWB antenna array pattern calculation ......................... 103
6.2.2 UWB antenna array PSF representation ....................... 104
6.3 Existing 2-D imaging array design approaches ......................... 107
6.4 Investigation of UWB antenna array behavior ........................... 108
6.4.1 Sidelobe behavior with respect to element spacing ....... 108
6.4.2 Impact of antenna mutual coupling ................................ 109
6.5 MIMO antenna array design ......................................................... 113
6.5.1 Linear MIMO array design based on linear uniformly
spaced effective array approach .................................... 113
6.5.2 Linear MIMO array design based on optimization
algorithm ........................................................................ 115
6.5.3 Two-dimensional MIMO antenna array design .............. 116
6.6 Application-driven UWB antenna array design ......................... 117
6.6.1 System specifications .................................................... 118
6.6.2 One-dimensional MIMO array design using the
effective array approach ................................................ 118
6.6.3 One-dimensional array design using the optimization
algorithm approach ........................................................ 120
6.6.4 Two-dimensional UWB antenna array design ................ 122
6.7 Experimental verification ............................................................. 124
6.7.1 Coupling behavior analysis ............................................ 125
6.7.2 Measured PSF ............................................................... 128
6.7.3 Image of distributed targets in free space ...................... 130
6.8 Conclusions .................................................................................. 133
7. Conclusions and recommendations ...................................... 137
7.1 Results and novelties of this research ....................................... 137
7.2 Dissemination and utilization of the results .............................. 139
7.3 Recommendations ....................................................................... 140
Appendix A Introduction to equipment used .............................. 143
A.1 Programmable network analyzer ................................................ 143
A.2 24-port switch ............................................................................... 143
A.3 Antenna probes ............................................................................ 146
A.4 Customized mini-SMP to 2.4mm adaptor ................................... 147
Appendix B Introduction to LTCC ................................................ 149
B.1 Introduction to LTCC technology ............................................... 149
B.2 LTCC Process ............................................................................... 150
B.3 Material properties used in this thesis ....................................... 153
B.4 LTCC manufacturing terminology .............................................. 154
B.5 Design rules .................................................................................. 155
Appendix C List of antennas parameters .................................... 157
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C.1 Microwave antenna parameters .................................................. 157
C.2 K-band antenna parameters ........................................................ 157
C.3 M-band antenna parameters ........................................................ 158
Appendix D Projection slice method and element shadowing
effect…............ ......................................................................... 161
Appendix E Experimental verification of 1-D MIMO array ......... 163
List of Acronyms ............................................................................ 167
Summary….. .................................................................................... 169
Samenvatting .................................................................................. 173
Author’s publications ..................................................................... 177
Acknowledgement .......................................................................... 179
About the Author ............................................................................ 181
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