Modern Automotive Antenna Measurements

This book provides practical and theoretical aspects for automotive antenna measurements. It comprehensively covers all the information you need to design, develop, place, and use antennas and antenna systems in automotive applications. Special chapters are devoted to some of the most advanced topics in this area, including OTA measurements for Vehicle to Everything (V2X) applications, emulation of virtual drive testing, and specific topics for measurements of automotive RADAR systems. You will understand the various measurement techniques specifically for automotive antennas, including chamber design, absorbers, near-to-far field transformation, and some of the newest techniques such as the use of drones. The book presents both well accepted and standard practices and includes innovative methods that help you quickly adapt to the rapidly evolving field of automotive antenna testing today. This is an excellent reference for antenna engineers, automotive system designers, and anyone who measures and designs antennas for automotive applications. Artech House Antennas Library Modern Automotive Antenna Measurements 2 Contents 6 Chapter 1 Introduction to Automotive Antenna and Device Measurements 10 References 13 Chapter 2 Challenges and Figures of Merit in Automotive Measurements 16 2.1 Antenna Measurement 16 2.1.1 Antenna Gain and OTA Measurements 17 2.1.2 Calibration Antenna 21 2.1.3 Testing Parameters 23 2.2 NF versus FF Measurements 27 2.3 Introduction to Near Transformation Theory 32 2.4 Radiofrequency System 34 References 36 Chapter 3 NFFF Transformations 38 3.1 NF/FF Transformation based on Spherical Wave Expansion 39 3.1.1 SWE 39 3.1.2 Truncated SNF Measurements 52 3.1.3 Advanced SWE Techniques 58 3.2 Equivalent Current Technique 69 3.2.1 Formulation 69 3.2.2 Features 70 3.3 New Methods for NF-to-FF Transformations 72 3.3.1 Sparse Recovery of SWC 73 3.3.2 Optimal Sampling Interpolation 73 References 74 Chapter 4 Chamber Design and Analysis 80 4.1 Measurement Ranges 80 4.2 Design Criteria 82 4.2.1 Absorbers and Ferrites 82 4.2.2 Rectangular Chambers 85 4.2.3 Tapered Chambers 88 4.2.4 Chambers with Conductive Floors 89 4.3 Analysis Methods 90 4.3.1 Full-Wave Models 90 4.3.2 Ray-Tracer Solvers 90 4.3.3 Image Theory–Based Technique 92 4.3.4 Measurements with the Scaled Model Method 94 4.4 QZ Evaluation with Measurements 99 4.4.1 Field Probe Measurements Over QZ 99 4.4.2 Antenna Pattern Comparison 100 References 102 Chapter 5 Implementation and Calibration of Automotive Ranges 106 5.1 Absorber and Conductive Floor Systems 107 5.1.1 Gain Calibration 108 5.1.2 Gain Calibration Accuracy 110 5.1.3 Measurement Examples 112 5.2 FF Ranges 115 5.3 Single-Probe NF Systems 117 5.3.1 Use of Wideband Probes 120 5.3.2 Use of Wideband and Dual-Polarized Probes 123 5.4 Multiprobe NF Systems 129 5.4.1 Probe-Related Design Challenges 130 5.4.2 Sampling in MP Systems 131 5.4.3 Different Implementations of Automotive MP Systems 132 5.4.4 Low-Frequency Measurements 133 5.4.5 High-Frequency Measurements 134 5.5 Scaled Measurements 138 References 140 Chapter 6 OTA Measurements 142 6.1 OTA Test Setup 142 6.2 OTA Testing Parameters 143 6.3 OTA System Calibration 144 6.4 OTA Measurement Methods 145 6.4.1 NF to FF Transform Using Phase Recovery 145 6.4.2 Separate Measurements with Conducted RF 146 6.4.3 Two-Step Measurement or Combinational Method 147 6.4.4 Direct OTA Measurements 147 6.4.5 NF to Quasi-FF Transform Through Parallax 148 6.4.6 TRP/TIS Testing of Devices on a Limited Ground Plane 149 6.5 OTA Sampling 150 6.6 OTA Measurement Examples 151 6.7 MIMO OTA Testing 155 6.7.1 Introduction 155 6.7.2 Direct MIMO OTA Testing 156 6.7.3 Two-Stage Methods 159 References 160 Chapter 7 Advanced Post-Processing Techniques 164 7.1 Post-Processing by the Equivalent Current Method 165 7.1.1 Diagnostics and Filtering 165 7.1.2 Extrapolation of Truncated Areas 167 7.1.3 NF Calculation from the Equivalent Current 169 7.1.4 Link Between Measurements and Simulations 169 7.2 Investigation and Mitigation of Truncation Errors in Free-Space Automotive Systems 172 7.2.1 Case Study Description and Investigation of Truncation Errors Effect 172 7.2.2 Mitigation of Truncation Errors 174 7.3 Free-Space Response Retrieval in PEC-Based Automotive Systems 177 7.3.1 Spatial Filtering Techniques for PEC Removal 177 7.3.2 Example with Scaled Measurements 179 References 183 Chapter 8 Virtual Drive Testing 186 8.1 VDT 186 8.2 The Link Between Measurement and Simulation 189 8.3 Simulation of Complex Scenarios from Measurements 190 8.4 Different Ground Emulation of Measured Vehicle Antennas 192 8.5 V2V and V2X Coupling Evaluation 199 References 201 Chapter 9 In-Situ Acquisition Systems for Automotive Measurements: Drone and Handheld Approaches 204 9.1 Introduction 204 9.2 Airborne-Based Antenna Measurement Techniques 206 9.2.1 An Overview of Airborne-Based Antenna Measurement Techniques 206 9.2.2 Antenna Characterization by Means of Equivalent Currents 208 9.2.3 Application Example 211 9.3 Handheld Systems 217 9.3.1 An Overview of the Handheld System 217 9.3.2 Handheld System Description 217 9.3.3 Particular Characteristics of the Handheld System 219 9.3.4 Application Example 221 9.4 Final Remarks 222 References 225 Chapter 10 Practical Aspects of Automotive Measurements and Virtual-Drive Testing 230 10.1 Challenges for Automotive Antenna Measurements 230 10.1.1 Limitations of Automotive Antenna Measurement Range 230 10.1.2 Implications of the Car Body for Antenna Design and Measurements in the Installed State 234 10.2 Application-Oriented Post-Processing of Automotive Antenna Measurements 238 10.2.1 Phase Center Determination 238 10.2.2 Automotive Antenna Performance Indicators 241 10.3 Over-the-Air Vehicle-in-the-Loop Approach for System Validation in a Virtual Environment 243 10.3.1 Concept 243 10.3.2 LTE and V2X Emulation 245 10.3.3 Automotive Radar 249 References 255 About the Editors 262 About the Contributors 263 Index 268 Automobile,antenna;,Antenna,measurements;,Artech,House;,978-1-63081-849-4 Automobile antenna,Antenna measurements,Artech House,978-1-63081-849-4