Handbook of Reflector Antennas

Transcription

1 Handbook of Reflector Antennas and Feed Systems Volume I Theory and Design of Reflectors Satish K. Sharma Sudhakar Rao Lotfollah Shafai

2 Preface Acknowledgments ix x Introduction Introduction Reflector Antenna Basics Feed Sources for Reflector Antennas Analysis of Reflector Antennas Advanced Reflector Antenna Configurations Important Fundamental Parameters Organization of the Book 9 References 10 Numerical Techniques for Reflectors Introduction Reflector Geometry Using a Surface of Revolution Rays in a Parabola Geometric Optics Feed Modeling Analytical Feed Models Spherical Wave Expansion Feed Currents Expansion Feed Reflector Analysis Methods Aperture Method PO Analysis GO/GTD Analysis Shooting and Bouncing Analysis Moment Method Reflector Analysis Reflector Size Limitation Struts Polygon Struts Metal Space Frame Radome Dual Reflector Dual Grid Reflector 60 v

3 vi Contents 2.10 Reflector Coupling 63 Acknowledgments 64 References 64 Classical Reflector Antennas: Design Guidelines and Performance Characteristics Introduction General Conic-Section-Generated Reflectors Conic Sections Conic-Section-Generated Reflectors Parabolic Reflectors Geometrical Parameters Feed Patterns Edge Tapers and Feed Tapers Reflector Pattern Characteristics Off-Focus Feeds Beam Squint Symmetric Versus Offset Parabolic Configurations Folded-Optics Reflectors Cassegrain and Gregorian Reflectors The Equivalent Paraboloid Feed and Subreflector Blockage Sidelobes Efficiency Factors Offset Dual-Reflector Systems Antenna Noise Temperature Reflector Shaping Other Classical Reflectors Corner Reflectors Spherical Reflector Reflectors with Parabolic Arc 117 References 119 Reflector Antennas with Adaptive Apertures Introduction Theory and Overview Reflector Antenna Performance with Individual TEll5 TM01, and TE2i Modes of a Circular Waveguide Feed Reflector Antenna Performance with Dual Mode Feed Horns Symmetric Reflector with TEj + 1 TM01 Mode Feed Horn Offset Reflector with TEn + TM01 Mode Feed Horn Symmetric Reflector with TEn + TE21 Mode Feed Horn Offset Reflector with TEn + TE21 Mode Feed Horn Symmetric Reflector with a Tri-Mode Circular Waveguide Feed 145

4 vii Practical Triple-Mode Feed Horn Symmetric Reflector Antenna Performance with the Tri-Mode Feed Multiple Phase Center Offset Reflectors with TMn + TM21 Microstrip Patch Feeds 155 References 160 Reflector Shaping Introduction Reflector Shaping Considerations Reflector Shaping Techniques Frequency Re-Use Reflector Shaping Using Synthesis Techniques Shaping Limitations and Manufacturing Aspects 176 References 178 CHAPTER 6 Bifocal and Bicollimated Dual Reflector Antennas 6.1 Introduction 6.2 Bifocal Dual Reflector Antennas Cassegrain Configuration Gregorian Configuration 6.3 Multifocal Dual Reflector Antennas 6.4 Bicollimated Dual Reflector Antenna Design Procedure Polynomial Approximation Equivalent Gregorian Confocal Reflector Limiting Gregorian Confocal Reflector Phase Error Analysis Design Example 6.5 Bifocal and Bicollimated Dual Reflector Antenna Applications Acknowledgments Appendix A: Determination of the Parameters P, L, a, and d Appendix B: Three-Dimensional Ray Tracing Procedure References CHAPTER 7 Advanced Reflector Antennas Introduction Confocal Antenna System Side-Fed and Front-Fed Offset Cassegrain Antenna Systems Nonfocused Reflector Antenna Reconfigurable Reflector Antennas ADE Reflector Antennas 241 References 245

5 CHAPTER 8 Reflectarray Antennas Introduction General Design Guidelines Aperture Efficiency of Reflectarray and Comparison with Conventional Parabolic Reflector Illumination Efficiency Spillover Efficiency Polarization Efficiency Phase Efficiency Blockage Efficiency Dielectric and Conductor Loss Contribution of Scattering from Constituent Components of a Reflectarray to Its Near-Field and Far-Field Operation Different Types of Reflectarray Cell Elements Different Types of Reflectarray Antennas 274 Acknowledgments 284 References 289 About the Editors 295 List of Contributors 298 Index 299