Description
Book SynopsisA comprehensive review of the recent advances in anechoic chamberand reverberation chamber designs and measurements Anechoic and Reverberation Chambers is a guide to the latest systematic solutions for designing anechoic chambers that rely on state-of-the-art computational electromagnetic algorithms. This essential resource contains a theoretical and practical understanding forelectromagnetic compatibility and antenna testing. The solutions outlined optimise chamber performance in the structure, absorber layout and antenna positions whilst minimising the overall cost. The anechoic chamber designs are verified by measurement results from Microwave Vision Group that validate the accuracy of the solution. Anechoic and Reverberation Chambers fills this gap in the literature by providing a comprehensive reference to electromagnetic measurements, applications and over-the-air tests inside chambers. The expert contributors offer a summary of the latest developments in anechoic and reverber
Table of ContentsAbout the Authors xi
About the Contributors xiii
Acknowledgements xv
Acronyms xvii
1 Introduction 1
1.1 Background 1
1.1.1 Anechoic Chambers 1
1.1.2 Reverberation Chambers 3
1.1.3 Relationship between Anechoic Chambers and Reverberation Chambers 6
1.2 Organisation of this Book 6
References 8
2 Theory for Anechoic Chamber Design 11
2.1 Introduction 11
2.2 Absorbing Material Basics 11
2.2.1 General Knowledge 11
2.2.2 Absorbing Material Simulation 14
2.2.3 Absorbing Material Measurement 16
2.3 CEM Algorithms Overview 22
2.4 GO Theory 23
2.4.1 GO from Maxwell Equations 23
2.4.2 Analytical Expression of a Reflected Field from a Curved Surface 24
2.4.3 Alternative GO Form 28
2.5 GO-FEM Hybrid Method 29
2.6 Summary 30
References 30
3 Computer-aided Anechoic Chamber Design 35
3.1 Introduction 35
3.2 Framework 35
3.3 Software Implementation 35
3.3.1 3D Model Description 35
3.3.2 Algorithm Complexities 36
3.3.3 Far-Field Data 39
3.3.4 Boundary Conditions 40
3.3.5 RAM Description 41
3.3.6 Forward Algorithm 42
3.3.7 Inverse Algorithm 54
3.3.8 Post Processing 55
3.4 Summary 56
References 57
4 Anechoic Chamber Design Examples and Verifications 59
4.1 Introduction 59
4.2 Normalised Site Attenuation 59
4.2.1 NSA Definition 59
4.2.2 NSA Simulation and Measurement 60
4.3 Site Voltage Standing Wave Ratio 68
4.3.1 SVSWR Definition 68
4.3.2 SVSWR Simulation and Measurement 72
4.4 Field Uniformity 75
4.4.1 FU Definition 75
4.4.2 FU Simulation and Measurement 76
4.5 Design Margin 79
4.6 Summary 86
References 87
5 Fundamentals of the Reverberation Chamber 89
5.1 Introduction 89
5.2 Resonant Cavity Model 89
5.3 Ray Model 95
5.4 Statistical Electromagnetics 96
5.4.1 Plane-Wave Spectrum Model 96
5.4.2 Field Correlations 99
5.4.3 Boundary Fields 102
5.4.4 Enhanced Backscattering Effect 108
5.4.5 Loss Mechanism 109
5.4.6 Probability Distribution Functions 112
5.5 Figures of Merit 117
5.5.1 Field Uniformity 117
5.5.2 Lowest Usable Frequency 121
5.5.3 Correlation Coefficient and Independent Sample Number 121
5.5.4 Field Anisotropy Coefficients and Inhomogeneity Coefficients 124
5.5.5 Stirring Ratio 126
5.5.6 K-Factor 126
5.6 Summary 128
References 128
6 The Design of a Reverberation Chamber 133
6.1 Introduction 133
6.2 Design Guidelines 133
6.2.1 The Shape of the RC 133
6.2.2 The Lowest Usable Frequency 134
6.2.3 The Working Volume 135
6.2.4 The Q Factor 135
6.2.5 The Stirrer Design 137
6.3 Simulation of the RC 140
6.3.1 Monte Carlo Method 140
6.3.2 Time Domain Simulation 142
6.3.3 Frequency Domain Simulation 142
6.4 Time Domain Characterisation of the RC 145
6.4.1 Statistical Behaviour in the Time Domain 146
6.4.2 Stirrer Efficiency Based on Total Scattering Cross Section 151
6.4.3 Time-Gating Technique 163
6.5 Duality Principle in the RC 166
6.6 The Limit of ACS and TSCS 169
6.7 Design Example 172
6.8 Summary 174
References 174
7 Applications in the Reverberation Chamber 185
7.1 Introduction 185
7.2 Q Factor and Decay Constant 185
7.3 Radiated Immunity Test 192
7.4 Radiated Emission Measurement 193
7.5 Free-Space Antenna S-Parameter Measurement 196
7.6 Antenna Radiation Efficiency Measurement 199
7.6.1 Reference Antenna Method 199
7.6.2 Non-reference Antenna Method 200
7.7 MIMO Antenna and Channel Emulation 212
7.7.1 Diversity Gain Measurement 212
7.7.2 Total Isotropic Sensitivity Measurement 219
7.7.3 Channel Capacity Measurement 220
7.7.4 Doppler Effect 220
7.8 Antenna Radiation Pattern Measurement 223
7.8.1 Theory 223
7.8.2 Simulations and Measurements 228
7.8.3 Discussion and Error Analysis 238
7.9 Material Measurements 243
7.9.1 Absorption Cross Section 243
7.9.2 Average Absorption Coefficient 250
7.9.3 Permittivity 257
7.9.4 Material Shielding Effectiveness 263
7.10 Cavity Shielding Effectiveness Measurement 264
7.11 Volume Measurement 270
7.12 Summary 276
References 276
8 Measurement Uncertainty in the Reverberation Chamber 283
Xiaoming Chen, Yuxin Ren, and Zhihua Zhang
8.1 Introduction 283
8.2 Procedure for Uncertainty Characterisation 283
8.3 Uncertainty Model 283
8.3.1 ACF Method 284
8.3.2 DoF Method 285
8.3.3 Comparison of ACF and DoF Methods 286
8.3.4 Semi-empirical Model 289
8.4 Measurement Uncertainty of Antenna Efficiency 293
8.5 Summary 300
References 301
9 Inter-Comparison Between Antenna Radiation Efficiency Measurements Performed in an Anechoic Chamber and in a Reverberation Chamber 305
Tian-Hong Loh and Wanquan Qi
9.1 Introduction 305
9.2 Measurement Facilities and Setups 306
9.2.1 Anechoic Chamber 306
9.2.2 Reverberation Chamber 307
9.3 Antenna Efficiency Measurements 308
9.3.1 Theory 308
9.3.1.1 Radiation Efficiency Using the Anechoic Chamber 308
9.3.1.2 Radiation Efficiency Using the Reverberation Chamber 309
9.3.2 Comparison Between the AC and the RC 309
9.3.2.1 Biconical Antenna 309
9.3.2.2 Horn Antenna 312
9.3.2.3 MIMO Antenna 312
9.4 Summary 318
Acknowledgement 319
References 319
10 Discussion on Future Applications 323
10.1 Introduction 323
10.2 Anechoic Chambers 323
10.3 Reverberation Chambers 323
References 325
Appendix A Code Snippets 327
Appendix B Reference NSA Values 339
Appendix C Test Report Template 345
Appendix D Typical Bandpass Filters 351
Appendix E Compact Reverberation Chamber at NUAA 359
Appendix F Relevant Statistics 373
Index 379
