Reflectarray Antennas

PAYAM NAYERI, PhD, received his doctorate in electrical engineering from the University of Mississippi and holds a degree in applied physics. He is an Assistant Professor in the Electrical Engineering Department at Colorado School of Mines, USA. FAN YANG, PhD, earned his doctorate in electrical engineering from the University of California at Los Angeles (UCLA), in 2002. He is a Professor in the Electronic Engineering Department, Tsinghua University, China. ATEF Z. ELSHERBENI, PhD, is a Distinguished Chair Professor and Electrical Engineering Department Head at Colorado School of Mines, USA. He holds a doctorate in Electrical Engineering from Manitoba University, Canada.

• Foreword xiiiPreface xvAcknowledgments xvii1 Introduction to Reflectarray Antennas 11.1 Reflectarray Concept 11.2 Reflectarray Developments 21.3 Overview of this Book 5References 72 Analysis and Design of Reflectarray Elements 92.1 Phase‐Shift Distribution on the Reflectarray Aperture 92.2 Phase Tuning Approaches for Reflectarray Elements 132.2.1 Elements with Phase/Time‐Delay Lines 142.2.2 Elements with Variable Sizes 152.2.3 Elements with Variable Rotation Angles 162.3 Element Analysis Methods 182.3.1 Periodic Boundary Conditions and Floquet Port Excitation 192.3.2 Metallic Waveguide Simulators 192.3.3 Analytical Circuit Models 212.3.4 Comparison of Element Analysis Techniques 222.3.4.1 Comparison between PBC and Metallic Waveguides 232.3.4.2 Comparison between PBC and the Circuit Model 242.4 Examples of Classic Reflectarray Elements 262.4.1 Rectangular Patch with Phase‐Delay Lines 262.4.2 Variable Size Square Patch 302.4.3 Single Slot Ring Elements 332.5 Reflectarray Element Characteristics and Design Considerations 372.5.1 Frequency Behavior of Element Reflection Coefficients 372.5.2 Effects of Oblique Incidence Angles on Element Reflection Coefficients 372.5.3 Sources of Phase Error in Reflectarray Element Design 412.6 Reflectarray Element Measurements 43References 463 System Design and Aperture Efficiency Analysis 493.1 A General Feed Model 493.1.1 Models of Linearly Polarized and Circularly Polarized Feeds 503.1.2 Balanced Feed Models 513.2 Aperture Efficiency 533.2.1 Spillover Efficiency 533.2.2 Illumination Efficiency 543.2.3 Effects of Aperture Shape on Efficiency 553.2.4 Effects of Feed Location on Efficiency 593.3 Aperture Blockage and Edge Diffraction 603.3.1 Aperture Blockage and Offset Systems 603.3.2 Edge Taper and Edge Diffraction 633.4 The Analogy between a Reflectarray and a Parabolic Reflector 703.4.1 The Offset System Configurations 713.4.2 Analogous Offset Reflector 723.4.2.1 Transformation from Reflector to Reflectarray System 723.4.2.2 Transformation from Reflectarray to Reflector System 753.4.3 Example of Analogous Offset Systems 76References 774 Radiation Analysis Techniques 794.1 Array Theory Approach: The Robust Analysis Technique 804.1.1 Idealized Feed and Element Patterns 804.1.2 Element Excitations and Reflectarray Radiation Pattern 814.2 Aperture Field Approach: The Classical Analysis Technique 824.2.1 Complex Feed Patterns 824.2.2 Field Transformations from Feed to Aperture and Equivalent Surface Current 834.2.3 Near‐Field to Far‐Field Transforms and Reflectarray Radiation Pattern 854.3 Important Topics in Reflectarray Radiation Analysis 874.3.1 Principal Radiation Planes 874.3.2 Co‐ and Cross‐Polarized Patterns 894.3.3 Antenna Directivity 904.3.4 Antenna Efficiency and Gain 914.3.5 Spectral Transforms and Computational Speedup 944.4 Full‐Wave Simulation Approaches 964.4.1 Constructed Aperture Currents Under Local‐Periodicity Approximation 964.4.2 Complete Reflectarray Models 964.5 Numerical Examples 984.5.1 Comparison of the Array Theory and Aperture Field Analysis Techniques 984.5.1.1 Example 1: Reflectarray Antenna with a Broadside Beam 994.5.1.2 Example 2: Reflectarray Antenna with an Off‐Broadside Beam 1004.5.1.3 Comparison of Calculated Directivity versus Frequency 1034.5.2 Consideration in the Array Theory Technique: Element Pattern Effect 1054.5.3 Consideration in the Aperture Field Technique: Variations of Equivalence Principle 1064.5.4 Comparisons with Full‐Wave Technique 107References 1105 Bandwidth of Reflectarray Antennas 1135.1 Bandwidth Constraints in Reflectarray Antennas 1135.1.1 Frequency Behavior of Element Phase Error 1135.1.2 Frequency Behavior of Spatial Phase Delay 1155.1.3 Aperture Phase Error and Reflectarray Bandwidth Limitations 1185.2 Reflectarray Element Bandwidth 1215.2.1 Physics of Element Bandwidth Constraints 1215.2.2 Parametric Studies on Element Bandwidth 1225.3 Reflectarray System Bandwidth 1355.3.1 Effect of Aperture Size on Reflectarray Bandwidth 1355.3.2 Effects of Element on Reflectarray Bandwidth 140References 1446 Reflectarray Design Examples 1476.1 A Ku‐band Reflectarray Antenna: A Step‐by‐Step Design Example 1476.1.1 Feed Antenna Characteristics 1476.1.2 Reflectarray System Design 1506.1.3 Reflectarray Element Design 1536.1.4 Radiation Analysis 1566.1.5 Fabrication and Measurements 1596.2 A Circularly Polarized Reflectarray Antenna using an Element Rotation Technique 1656.3 Bandwidth Comparison of Reflectarray Designs using Different Elements 169References 1767 Broadband and Multiband Reflectarray Antennas 1797.1 Broadband Reflectarray Design Topologies 1797.1.1 Multilayer Multi‐Resonance Elements 1797.1.2 Single‐Layer Multi‐Resonance Elements 1817.1.3 Sub‐Wavelength Elements 1847.1.4 Reflectarrays Employing Single‐Layer and Double‐Layer Sub‐Wavelength Elements 1887.1.5 Broadband Design Methods for Large Reflectarrays 1977.2 Phase Synthesis for Broadband Operation 1977.2.1 A Phase Synthesized Broadband Reflectarray 2007.2.2 A Dual‐Frequency Broadband Reflectarray 2037.3 Multiband Reflectarray Designs 2067.3.1 A Single‐Layer Dual‐Band Circularly Polarized Reflectarray 2107.3.2 A Single-Layer Tri-Band Reflectarray 213References 2218 Terahertz, Infrared, and Optical Reflectarray Antennas 2278.1 Above Microwave Frequencies 2278.2 Material Characteristics at Terahertz and Infrared Frequencies 2288.2.1 Optical Measurements and Electromagnetic Parameters 2288.2.2 Measured Properties of Conductors and Dielectric Materials 2298.2.3 Calculating Drude Model Parameters for Conductors 2298.3 Element Losses at Infrared Frequencies 2348.3.1 Conductor Losses 2348.3.1.1 Effect of Conductor Thickness 2348.3.1.2 Effect of Complex Conductivity 2378.3.2 Dielectric Losses 2408.3.3 Effect of Losses on Reflection Properties of Elements 2418.3.4 Circuit‐Model Analysis 2428.3.4.1 Circuit Theory and Loss Study 2428.3.4.2 Zero‐Pole Analysis of Element Performance 2438.4 Reflectarray Design Methodologies and Enabling Technologies 2458.4.1 Reflectarrays with Patch Elements 2458.4.2 Dielectric Resonator Reflectarrays 2488.4.3 Dielectric Reflectarrays 2518.4.3.1 Dielectric Property and 3D Printing Technique 2518.4.3.2 Dielectric Reflectarray Design 2538.4.3.3 Dielectric Reflectarray Prototypes and Measurements 2598.5 Future Trends 261References 2649 Multi‐Beam and Shaped‐Beam Reflectarray Antennas 2679.1 Direct Design Approaches for Multi‐Beam Reflectarrays 2689.1.1 Geometrical Aperture Division 2689.1.2 Superposition of Aperture Fields 2719.1.3 Comparison of Direct Design Approaches 2729.2 Synthesis Design Approaches for Shaped‐ and Multi‐Beam Reflectarrays 2759.2.1 Basics of Synthesis Techniques 2759.2.2 Local‐Search Techniques 2769.2.3 Global‐Search Techniques 2799.2.4 Full‐Wave Optimization Design Approaches 2809.3 Practical Reflectarray Designs 2819.3.1 Single‐Feed Reflectarray with Multiple Symmetric Beams 2819.3.2 Feed Reflectarrays with Multiple Asymmetric Beams 2869.3.3 Shaped‐Beam Reflectarrays 2949.3.4 Multi‐Feed Multi‐Beam Reflectarrays 297References 30010 Beam‐Scanning Reflectarray Antennas 30310.1 Beam‐Scanning Approaches for Reflectarray Antennas 30410.1.1 Design Methodologies 30410.1.2 Classifications Based on Reflector Type 30610.2 Feed‐Tuning Techniques 30710.2.1 Fully Illuminated Single‐Reflector Configurations 30710.2.1.1 Parabolic‐Phase Apertures 30710.2.1.2 Non‐Parabolic‐Phase Apertures 31310.2.2 Partially Illuminated Single‐Reflector Configurations 32410.2.2.1 Parabolic Cylindrical‐Phase Reflectarray Antennas (pcpra) 32410.2.2.2 Parabolic Torus‐Phase Reflectarray Antennas (PTPRA) 32910.2.2.3 Spherical‐Phase Reflectarray Antennas (SPRA) 33110.2.3 Dual‐Reflector Configurations 33410.2.3.1 Parabolic Reflector/Reflectarray Antennas 33410.2.3.2 Non‐Parabolic Reflector/Reflectarray Antennas 33610.2.4 Summary of Feed‐Tuning Techniques 33710.3 Aperture Phase‐Tuning Techniques 33910.3.1 Basics of Aperture Phase Tuning 33910.3.2 Enabling Technologies 34110.3.2.1 Mechanical Actuators/Motors 34110.3.2.2 Electronic Devices 34310.3.2.3 Functional Materials 35210.4 Frontiers in Beam‐Scanning Reflectarray Research 35510.4.1 Active Reflectarrays 35510.4.2 Comparison Between Analog and Digital Phase Control 35510.4.3 Sub‐Array Techniques 35810.4.4 Hybrid Configurations 359References 35911 Reflectarray Engineering and Emerging Applications 36711.1 Advanced Reflectarray Geometries 36711.1.1 Conformal Reflectarrays 36711.1.1.1 Analysis of Conformal Reflectarrays 36711.1.1.2 Radiation Characteristics of Conformal Reflectarrays on Cylindrical Surfaces 36911.1.2 Dual‐Reflectarrays 37511.2 Reflectarrays for Satellite Applications 37911.2.1 An L‐Band Reflectarray for the Beidou Satellite System 38111.2.2 Reflectarrays Integrated with Solar Cells 38411.3 Power Combining and Amplifying Reflectarrays 38811.4 A Perspective on Reflectarray Antennas 39311.4.1 Large‐Aperture Planar Reflectarray Antennas 39311.4.2 Reflectarray Antennas with Broad Bandwidth, Beam‐Scanning Capability, and Low Cost 39611.4.3 From Reflectarray Antennas to Transmitarray Antennas 396References 397Index 401