PRACTICAL ASPECTGS OF ACTIVE PHASED ARRAY ANTENNA DEVELOPMENT

A culmination of Ashok Agrawal's 35 years of experience working on active phased array antenna systems this comprehensive guide covers design and development of an active phased array antenna system involving inputs from multiple disciplines such as aperture design, T/R module design, hybrid lab, beam steering control, mechanical engineering, and manufacturing. With key topics covered such as radar system-level advantages of active phased arrays over passive phased arrays such as Increased sensitivity, Improved Target Detection in Clutter, Improved Waveform and Pattern Flexibility, Improved Wideband Operation, Increased reliability, Reduced Cost, broadband frequency operation, lower noise temperature/figure, and reduction in prime power. This book will be beneficial to new engineers as well as experienced engineers working on active phased array antenna systems. Practical Aspects of Active PhasedArray Antenna Development Contents Preface 1Practical Aspects of Active Phased Array Antenna Development 1.1 Introduction 1.2 Active Phased Array Antenna System 1.3 Passive Phased Array Antenna 1.4 Passive Phased Array Antenna Limitations 1.5 Active Phased Array Antenna 1.6 Key Radar System-level Advantages of Active Phased Arrays over Passive Phased Arrays 1.6.1 Increased Sensitivity 1.6.2 Improved Target Detection in Clutter 1.6.3 Improved Waveform and Pattern Flexibility 1.6.4 Improved Wideband Operation 1.6.5 Increased Reliability 1.6.6 Reduced Prime Power Requirement 1.6.7 Reduced Cost 1.6.8 Lower Noise Temperature/Figure 1.6.9 Adaptive and Digital Beamforming 1.7 Tracking Radar Performance Metric 1.8 Introductions to the Chapters 1.9 Concluding Remarks References 2Analysis and Design of Linear and Planar Phased Arrays 2.1 Introduction 2.2 Analysis of Linear Arrays 2.3 Low Sidelobes for Linear Arrays 2.4 Low Sidelobe Aperture Distributions 2.4.1 Dolph-Chebyshev Aperture Distribution 2.4.2 Taylor Distribution for Linear Arrays 2.4.3 Bayliss Distribution for Difference Patterns 2.4.4 Implementation of Monopulse Beams for an Active Planar Phased Array Antenna 2.5 Analysis and Synthesis of Planar Arrays 2.5.1 Rectangular Grid 2.5.2 Triangular Array Element Grid 2.6 Comparison of Rectangular and Triangular Grids 2.7 Minimize the Number of Elements for a Grating Lobe-free Pattern Using a Tilted Array 2.8 Directivity and Gain of Active Arrays 2.9 Effect of Amplitude and Phase Errors on the Phased Array Antenna Performance 2.9.1 Quantization Errors 2.9.2 RMS Sidelobe Level Due to Amplitude and Phase Errors 2.10 Beam Pointing Error Due to Phase Quantization 2.11 Bandwidth Criteria for Active Phased Array Antennas 2.11.1 Instantaneous Bandwidth 2.11.2 Phased Array Operating Bandwidth 2.12 Moderate Instantaneous Wide Bandwidth Array by Applying Amplitude Taper in the Receiver 2.13 Concluding Remarks References 3Transmit/Receive Modules 3.1 Introduction 3.2 T/R Module Architecture 3.2.1 Control Module 3.2.2 Integration of T/R Module with DC-to-DC Converter 3.2.3 Shared Leg T/R Module Architecture 3.3 Active Phased Array Performance Improvement 3.3.1 GaN Wide Bandgap Power Amplifiers 3.4 T/R Module Key Performance Parameters 3.4.1 Power-Added Efficiency 3.4.2 T/R Module Noise Figure 3.4.3 Noise Figure of a Cascaded Network 3.4.4 T/R Module Noise Temperature 3.4.5 1-dB Compression Point 3.4.6 Third-Order Intercept Point 3.5 T/R Module Architecture Tradeoffs 3.6 T/R Module Architectures for Circular Polarization 3.7 T/R Module Construction 3.8 Thermal Stack-Up of the T/R Module 3.9 Integration of MMIC, Control Module, and DC-to-DC Converters 3.10 T/R Module Stability 3.11 T/R Module Reliability 3.12 T/R Module Cost 3.13 Performance Requirements of T/R Modules 3.14 Application of Silicon Germanium (SiGe) BiCMOS Technology in T/R Modules 3.15 Concluding Remarks References 4Beamformer Architectures for Active Phased Array Antennas 4.1 Introduction 4.2 Beamformer Networks for Passive Phased Array Antennas 4.3 Beamformer Networks for Active Phased Array Antennas 4.3.1 Multiple Independent Receive Beams 4.4 Impact of Beamformer Architecture on System Noise Temperature 4.5 Beamformer Architectures for High Reliability 4.6 Beamformer Networks for Wideband Active Phased Array Antennas 4.7 Concluding Remarks References 5Radiating Elements 5.1 Introduction 5.2 Printed Circuit Radiating Elements 5.2.1 Printed Circuit Wideband Radiating Elements 5.3 Waveguide Radiating Elements 5.3.1 A Wideband Tapered Double-Ridged Waveguide Element Fed by a Coaxial Probe 5.4 Radome Heating for Ice Inhibition 5.5 Wideband Parallel Waveguide Phased Array Radiator 5.6 Mutual Coupling Between Radiating Elements 5.7 Selection of the Radiating Element Type 5.8 Radiating Element Design Process 5.9 Phased Array Radiation Pattern Calculation by Using the Mutual Coupling Between Elements in a Small Array 5.10 Concluding Remarks References 6Beam Steering and DC Power Distribution 6.1 Active Phased Array Antenna Beam Steering Controller 6.1.1 Active Phased Array Distributed Beam Steering Controller 6.1.2 Active Phased Array Centralized Beam Steering Controller 6.2 Active Phased Array Power Distribution 6.2.1 DC-to-DC Converter Key Requirements 6.2.2 Distributed Power System 6.2.3 Centralized Power System 6.2.4 Average versus Peak DC-to-DC Converters 6.2.5 Comparison of Distributed and Centralized Power Systems 6.3 Concluding Remarks References 7Active Phased Array Antenna Packaging 7.1 Introduction 7.2 Array Packaging Concepts 7.2.1 Tile Array Construction and Cooling Methods 7.2.2 Brick Array Packaging 7.2.3 Components of an LRU 7.2.4 Thermal Management 7.3 Active Array Antenna Brick Packaging Schemes 7.3.1 Sliding Vertical Cold Plate Active Array Packaging 7.3.2 Edge-Cooled, Horizontal Cold Plate Array Packaging 7.3.3 Vertical Fixed Cold Plate Packaging Concept 7.4 LRU to the Radiating Element RF Connections 7.5 Structural Design 7.6 Active Array Antenna Radome Design 7.7 Concluding Remarks References 8Active Phased Array Antenna Design for High Reliability 8.1 Introduction 8.2 Antenna MTBF 8.3 Active Phased Array Antenna Architecture Description for High Reliability 8.4 Maximizing the Array MTBCF 8.5 Antenna MTBF for Different Cluster Sizes 8.6 Increasing Array MTBCF with Redundant Power Supplies 8.7 Driver Amplifier Boosters in the Active Phased Array Beamformers 8.8 Lifecycle Maintenance Cost Estimation of an Active Phased Array Antenna 8.9 Active Phased Array Antenna Availability and Sparing 8.10 Concluding Remarks References 9Active Phased Array Design for High Clutter Improvement Factor 9.1 Introduction 9.2 Centralized Phased Array Architecture 9.3 Distributed Array Architecture 9.4 Concluding Remarks References 10Active Phased Array Antenna Calibration 10.1 Introduction 10.2 Active Array Calibration Using Mutual Coupling Between Array and External Elements 10.3 Active Array Calibration Technique Using Mutual Coupling Between Array Elements 10.4 Active Array Calibration Technique Using Mutual Coupling Between a Few Dedicated Internal Elements and the Array Elements 10.4.1 Calibration Procedure 10.4.2 Required Number of Calibration Elements 10.4.3 Calibration Accuracy 10.4.4 Effect on Array Packaging 10.5 Concluding Remarks References 11Digital Beamforming for Active Phased Array Antennas 11.1 Introduction 11.2 Dynamic Range Improvement 11.3 Digital Beamforming at Subarray Level 11.4 Digital Beamforming of Multiple Simultaneously Independent Receiver Beams 11.5 Angle Tracking Accuracy 11.6 Adaptive Digital Beamforming 11.6.1 Adapting Nulling in Analog Arrays 11.7 Exciter Noise and Clutter Attenuation 11.8 Concluding Remarks References 12Cost Reduction Strategies for Active Phased Array Antennas 12.1 Introduction 12.2 High Cost of Current Active Phased Array Antennas 12.3 SPY-1 Array Antenna Cost Reduction 12.4 Improvements in Technology and Manufacturing Processes 12.5 Paradigms 12.5.1 Legacy Systems 12.5.2 Commercial Parts and Processes Are Not Adequate for Military Applications 12.5.3 Cost-Plus Contracts 12.5.4 Lack of Incentives 12.5.5 Schedule Limitations Do Not Permit Any Design Changes 12.5.6 The Benefits of Competition to the Buyer: An Automobile Industry Example 12.5.7 Use the Best Available Technology 12.5.8 Changes Will Increase Program Costs and Schedule Delays 12.6 Design Philosophy 12.6.1 Bottom-Up 12.6.2 Top-Down 12.7 Cost Reduction Strategies 12.7.1 Optimizing T/R Module RF Output Power Levels for Phased Array Antenna Cost, Size, Prime Power, and Dissipated Heat 12.7.2 Trading the Number of Array Faces for a Hemispherical Field of View 12.7.3 Band-Aid Solutions 12.7.4 Antenna Architecture 12.7.5 Minimize the Number of Interfaces 12.7.6 LRU Size versus Cost 12.7.7 Radiating Element 12.7.8 T/R Modules 12.7.9 Module Packaging 12.7.10 DC Power Distribution 12.7.11 Beamformers, Cables, and Connectors 12.7.12 Power-Added-Efficiency and Cost 12.7.13 Active Phased Array Antennas for Wide Bandwidth Operation 12.7.14 Antenna Assembly and Test 12.8 Concluding Remarks References Appendix: T/R Module Requirements and Flow Down to the Components T/R Module Requirements Flow Down (Receive Channel) About the Author Index