Table Of ContentHandbook of Reflector Antennas
and Feed Systems
Volume III
Applications of Reflectors
For a listing of recent titles in the
Artech House Antennas and Propagation Series,
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Handbook of Reflector Antennas
and Feed Systems
Volume III
Applications of Reflectors
Sudhakar Rao
Lotfollah Shafai
Satish Sharma
Editors
‑Library of Congress Cataloging‑in‑Publication Data
A catalog record for this book is available from the U.S. Library of Congress.
British Library Cataloguing in Publication Data
A catalog record for this book is available from the British Library.
ISBN-13: 978-1-60807-519-5
Cover design by Vicki Kane
Cover photos:
Top picture: An Intelsat satellite that employs multiple reflector antennas to provide
shaped beams over a wide area of landmass (courtesy of Intelsat Corporation).
Middle picture: C-band integrated compact feed assembly with dual-polarization,
high-power, and low-PIM capability used for uplink and downlink communications
links for fixed satellite services (courtesy of Custom Microwave, Inc.).
Bottom picture: Ibaraki No. 3 Earth Station Antenna (29.6m) (courtesy of MELCO,
Japan).
© 2013 Artech House
All rights reserved. Printed and bound in the United States of America. No part
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All terms mentioned in this book that are known to be trademarks or service
marks have been appropriately capitalized. Artech House cannot attest to the
accuracy of this information. Use of a term in this book should not be regarded
as affecting the validity of any trademark or service mark.
10 9 8 7 6 5 4 3 2 1
Contents
Preface xi
CHAPTER 1
Introduction 1
1.1 Introduction 1
1.2 Reflector Antenna Basics 4
1.3 Organization of Book Chapters 7
References 11
CHAPTER 2
Reflector Antennas for Space Communications 13
2.1 Introduction 13
2.2 Contoured Beam Antennas 18
2.2.1 Single-Offset Shaped Reflector Antenna for Contoured Beams 19
2.2.2 Dual-Offset Gregorian Reflectors 27
2.2.3 Gridded-Reflector Antennas 32
2.3 Multiple-Beam Antennas 39
2.3.1 Introduction 39
2.3.2 Frequency Reuse Schemes 43
2.3.3 Multiple-Beam Antenna Types 46
2.3.4 Design and Analysis of Multiple-Beam Reflector Antennas 51
2.3.5 Multiple-Beam Antenna Design Examples for Various
Satellite Services 68
References 75
CHAPTER 3
Reflector Antennas for Terrestrial Communications 77
3.1 Introduction 77
3.2 Large Earth Station Reflector Antenna 78
3.2.1 Design Method 78
3.2.2 Main Performance 83
v
vi Contents
3.3 Tri-Reflector Offset Antenna for Terrestrial Microwave Relay
Link Systems 85
3.3.1 Electrical Design 87
3.3.2 Structural Design 96
3.3.3 Main Performance of a Prototype Antenna 98
3.4 Shaped Beam Horn Reflector Antenna for 20/30-GHz-Band
Communication Systems 101
3.4.1 Design 102
3.4.2 Performance 108
3.5 Offset-Shaped Dual-Reflector Antenna with an Elliptical Aperture
for Satellite News Gathering 109
3.5.1 Reflector Design 109
3.5.2 Mechanical Structure 113
3.5.3 Main Performance 115
3.6 Low-Profile Dual-Shaped Reflector Antenna with an Elliptical
Aperture for Aeronautical Satellite Communication Systems 116
3.6.1 Design Method 117
3.6.2 Main Performance 122
3.7 Compact Reflector Antenna for Ku-Band ESV and VSAT 125
3.7.1 Compact Reflector Antenna Problems 126
3.7.2 Design Example 128
3.7.3 Main Performance 130
3.8 Single-Reflector Wide-Beam-Spacing Multibeam Antennas 132
3.8.1 Design 133
3.8.2 Performance 135
3.9 Multisector Omnidirectional Offset-Shaped Reflector Antenna for
26-GHz-Band Fixed Wireless Access Base Station 135
3.9.1 Design 136
3.9.2 Performance 140
References 141
CHAPTER 4
Reflector Antennas for Terahertz Imaging Applications 145
4.1 Introduction 145
4.2 Reflector Systems Focusing in the Fresnel Region 150
4.2.1 Focusing in the Fresnel or Fraunhofer Region 151
4.2.2 Field in the Target Plane of a Focusing Reflector 152
4.2.3 General Properties of the Field in the Target Plane 156
4.2.4 Equivalence Between Offset Parabolic and Elliptical Reflectors 162
4.3 Imaging with Focal Plane Arrays 166
4.3.1 Relationship Between the Reflector Aperture Efficiency and
the Power Received by an Antenna in the Focal Plane of the Reflector 167
4.3.2 Focal Plane Sampling in Active Systems 170
4.3.3 Focal Plane Sampling in Passive Systems 178
4.3.4 Typical Reflector Systems 183
4.4 Imaging with Mechanical Scanners 186
Contents vii
4.4.1 Types of Mechanical Scanners 186
4.4.2 Typical Reflector Systems 197
Appendix 4A Derivation of Field in the Focal Plane of a Focusing
Reflector 199
Appendix 4B Effective Height of the Reflector Antenna Feed 204
Appendix 4C Power Received by an Antenna in the Focal Plane of
a Focusing Reflector 207
Appendix 4D Integration Time in Passive Detectors 208
Appendix 4E Instrument Background Contribution 210
References 211
CHAPTER 5
Multiband Reflector Antennas 215
5.1 Introduction 215
5.2 Dual-Band Reflector Antennas with Single Feeds 216
5.3 Dual-Band Reflector Antennas with Multiple Feeds 219
5.4 Multiband Antennas Supporting Several Frequency Bands 224
5.4.1 Tri-Band Antenna 224
5.4.2 Multiband Antenna Supporting Five Frequency Bands 228
5.5 Stepped-Reflector Antenna 236
5.6 Reflector Antenna with Reflective and Partially Reflective Surfaces 238
References 241
CHAPTER 6
Reflector Antennas for Remote Sensing Applications 243
6.1 Introduction 243
6.2 Solid Nondeployable Composite Reflectors 244
6.2.1 Voyager/Magellan 244
6.2.2 Cassini 247
6.2.3 CloudSat 249
6.2.4 Aquarius 252
6.2.5 Mars Reconnaissance Orbiter (MRO) 254
6.2.6 JASON Advanced Microwave Radiometer Antenna 255
6.3 Deployable Reflector Antennas 257
6.3.1 Deployable Composite Reflectors 257
6.3.2 Deployable Mesh Reflectors 259
6.3.3 Reflectarrays 265
6.3.4 Inflatable Reflectors and Structures 269
6.4 Summary 275
Acknowledgments 276
References 276
CHAPTER 7
Feed Assemblies, Passive Intermodulation, Multipaction, and Corona 279
7.1 Introduction 279
7.2 Feed Components 280
viii Contents
7.2.1 Bends 280
7.2.2 Transitions 281
7.2.3 Filters 282
7.2.4 E-Plane, H-Plane, and Magic Tees 283
7.2.5 Orthomode Transducers 284
7.2.6 Polarizers 287
7.2.7 Horns 289
7.3 Feed Design 289
7.3.1 Integrated Design Approach 290
7.3.2 Other Key RF Design Considerations 290
7.3.3 Precision RF CAD Tools 291
7.3.4 Mechanical and Thermal Design 292
7.3.5 Manufacturing Methods 293
7.4 Feed Examples 295
7.4.1 Standard C-Band Feed 295
7.4.2 Standard Ku-Band Feeds 296
7.4.3 K-Ka-Band Feed 299
7.4.4 Low Profile K-Ka-Band Network for Feed Array 299
7.4.5 K-Ka-Q-Band Network 300
7.4.6 Ku-Band Tracking Feed 301
7.5 Qualification and Protoflight Testing 302
7.6 Feed Assembly Deleterious High-Power RF Effects: Passive
Intermodulation, Gas Ionization/Corona, and Multipactor 304
7.7 Passive Intermodulation 305
7.7.1 The PIM Problem 305
7.7.2 PIM Defined 306
7.7.3 Causes of PIM 307
7.7.4 Mathematical Definition [18, 19] 309
7.7.5 PIM as a Function of Incident Power 311
7.7.6 PIM Mitigation 312
7.7.7 Susceptible Systems 313
7.7.8 Hardware PIM Requirements 313
7.7.9 PIM Test and Verification Methods 314
7.8 Multipactor, Corona, and Ionization Breakdown 320
7.8.1 Multipactor 321
7.8.2 Corona and Ionization Breakdown 324
7.8.3 Hardware Test Requirements 325
Appendix 7A 331
7A.1 Generic PIM Test Setup Equations Related to Far-Field Tx
Flux Density 331
Appendix 7B 332
7B.1 Generic PIM Test Setup Equations Related to Far-Field Rx
Coupling 332
Appendix 7C 333
7C.1 Example Test Procedure 333
References 338
Contents ix
CHAPTER 8
Deployable Reflectors 341
8.1 Introduction 341
8.2 Reflector Classifications 342
8.2.1 Classifications According to Reflector Surface Geometry 342
8.2.2 Classification According to Reflector Surface Type 344
8.3 Segmented Reflectors 345
8.4 Semirigid Surface Reflectors: Spring-Back Antennas 347
8.5 Inflatable/Rigidizable Reflectors 349
8.6 Woven-Mesh Surface: The Wrap-Rib Reflector 352
8.7 Knitted-Mesh Surface Reflectors 354
8.7.1 The Knitted Mesh 354
8.7.2 The Shaping Net/Soft Structure 356
8.7.3 The Deploying Structure 360
8.7.4 Mesh and Soft-Structure Management Provisions 373
8.8 Reflector Subsystem Design Considerations 375
8.8.1 Electrical Requirements 376
8.8.2 Mechanical Requirements 380
8.8.3 Thermal and Environmental Requirements 382
References 382
CHAPTER 9
Mechanical Aspects of Reflector Antennas for Space Applications 385
9.1 Mechanical Considerations for Spaceflight Antenna Reflectors 385
9.2 Spaceflight Reflector Design Requirements 386
9.2.1 RF Requirements 387
9.2.2 Mechanical Requirements 387
9.2.3 Reflector Geometries 389
9.3 Mechanical Design Considerations 391
9.3.1 Reflector Support Points and Interfaces 391
9.3.2 Mass 392
9.3.3 Stiffness 393
9.3.4 Stability 393
9.3.5 Dynamics Considerations 394
9.3.6 Acoustics Considerations 395
9.3.7 Thermal Considerations 397
9.4 Construction Considerations 398
9.4.1 Design Configuration 398
9.4.2 Reflector Construction Materials 400
9.5 Manufacturing Considerations 407
9.5.1 Mold Tooling 407
9.5.2 Mold Tool Surface Accuracy 407
9.5.3 Mold Tool Design Considerations 410
9.5.4 Mold Tool Material Options 411
9.5.5 Composite Fabrication Equipment Requirements 414
