Electromagnetic Shielding

Electromagnetic Shielding......Page 4
Contents......Page 8
Preface......Page 14
1.1 Definitions......Page 16
1.2 Notation, Symbology, and Acronyms......Page 18
1.3.1 Macroscopic Electromagnetism and Maxwell’s Equations......Page 19
1.3.2 Constitutive Relations......Page 21
1.3.3 Discontinuities and Singularities......Page 24
1.3.5 Poynting’s Theorem and Energy Considerations......Page 26
1.3.6 Fundamental Theorems......Page 28
1.3.7 Wave Equations, Helmholtz Equations, Electromagnetic Potentials, and Green’s Functions......Page 30
1.5 Source Inside or Outside the Shielding Structure and Reciprocity......Page 33
References......Page 34
2.1 Standard Metallic and Ferromagnetic Materials......Page 36
2.2 Ferrimagnetic Materials......Page 42
2.3 Ferroelectric Materials......Page 43
2.4 Thin Films and Conductive Coatings......Page 45
2.5.2 Conductive Polymers......Page 47
2.6.1 Metamaterials and Chiral Materials......Page 48
2.6.2 Composite Materials......Page 51
2.6.4 High-Temperature Superconductors......Page 52
References......Page 53
3.1 (Local) Shielding Effectiveness......Page 57
3.2 The Global Point of View......Page 60
3.3 Other Proposals of Figures of Merit......Page 61
3.4 Statistical Methods......Page 65
3.5 Energy-Based, Content-Oriented Definition......Page 67
References......Page 68
4.1 Electromagnetic Plane Waves: Definitions and Properties......Page 70
4.2.1 Transmission-Line Approach......Page 73
4.2.2 The Single Planar Shield......Page 76
4.2.3 Multiple (or Laminated) Shields......Page 81
4.3 Plane Waves Normally Incident on Cylindrical Shielding Surfaces......Page 82
4.4 Plane Waves against Spherical Shields......Page 89
4.5 Limits to the Extension of the TL Analogy to Near-Field Sources......Page 90
References......Page 99
5 Numerical Methods for Shielding Analyses......Page 102
5.1 Finite-Element Method......Page 104
5.2 Method of Moments......Page 114
5.3 Finite-Difference Time-Domain Method......Page 125
5.4 Finite Integration Technique......Page 134
5.5 Transmission-Line Matrix Method......Page 139
5.6 Partial Element Equivalent Circuit Method......Page 142
5.7 Case Study: Scattering from a Perfectly Conducting Enclosure with a Rectangular Aperture......Page 149
References......Page 152
6 Apertures in Planar Metal Screens......Page 159
6.1 Historical Background......Page 160
6.2 Statement of the Problem......Page 161
6.3 Low-Frequency Analysis: Transmission through Small Apertures......Page 162
6.4 The Small Circular-Aperture Case......Page 163
6.5 Small Noncircular Apertures......Page 169
6.6 Finite Number of Small Apertures......Page 170
6.7 Rigorous Analysis for Apertures of Arbitrary Shape: Integral Equation Formulation......Page 172
6.8 Rules of Thumb......Page 175
References......Page 176
7 Enclosures......Page 179
7.1 Modal Expansion of Electromagnetic Fields inside a Metallic Enclosure......Page 180
7.2 Oscillations inside an Ideal Source-Free Enclosure......Page 183
7.3 The Enclosure Dyadic Green Function......Page 184
7.4 Excitation of a Metallic Enclosure......Page 187
7.5 Damped Oscillations inside Enclosures with Lossy Walls and Quality Factor......Page 188
7.6 Apertures in Perfectly Conducting Enclosures......Page 190
7.6.1 Small-Aperture Approximation......Page 191
7.6.2 Rigorous Analysis: Integral-Equation Formulation......Page 193
7.6.3 Aperture-Cavity Resonances......Page 195
7.7 Small Loading Effects......Page 198
7.8 The Rectangular Enclosure......Page 199
7.8.1 Symmetry Considerations......Page 202
7.9 Shielding Effectiveness of a Rectangular Enclosure with a Circular Hole......Page 203
7.9.1 External Sources: Plane-Wave Excitation......Page 204
7.9.2 Internal Sources: Electric and Magnetic Dipole Excitations......Page 207
References......Page 213
8 Cable Shielding......Page 215
8.1 Transfer Impedance in Tubular Shielded Cables and Aperture Effects......Page 216
8.2 Relationship between Transfer Impedance and Shielding Effectiveness......Page 221
8.3 Actual Cables and Harnesses......Page 222
References......Page 223
9.1 Gaskets......Page 225
9.2 Shielded Windows......Page 229
9.3 Electromagnetic Absorbers......Page 230
9.5 Air-Ventilation Systems......Page 231
References......Page 232
10 Frequency Selective Surfaces......Page 234
10.1.1 Floquet’s Theorem and Spatial Harmonics......Page 235
10.1.2 Plane-Wave Incidence on a Planar 1D Periodic Structure......Page 237
10.1.3 Plane-Wave Incidence on a Planar 2D Periodic Structure......Page 238
10.2 High- and Low-Pass FSSs......Page 240
10.3 Band-Pass and Band-Stop FSSs......Page 243
10.3.1 Center-Connected Elements or N-Pole Elements......Page 244
10.3.3 Solid-Interior-Type Elements......Page 245
10.4 Degrees of Freedom in Designing FSSs......Page 246
10.5 Reconfigurable and Active FSSs......Page 247
10.6 FSSs and Circuit Analog Absorbers......Page 249
10.7 Modeling and Design of FSSs......Page 250
References......Page 251
11 Shielding Design Guidelines......Page 256
11.1 Establishment of the Shielding Requirements......Page 257
11.2 Assessment of the Number and Types of Functional Discontinuities......Page 258
11.3 Assessment of Dimensional Constraints and Nonelectromagnetic Characteristics of Materials......Page 259
11.4 Estimation of Shielding Performance......Page 260
References......Page 261
12.1 Active Shielding......Page 262
12.2 Partial Shields......Page 267
12.3 Chiral Shielding......Page 270
12.4 Metamaterial Shielding......Page 271
References......Page 275
Appendix A Electrostatic Shielding......Page 278
A.1 Basics Laws of Electrostatics......Page 279
A.2 Electrostatic Tools: Electrostatic Potential and Green’s Function......Page 281
A.3.1 Conductive Electrostatic Shields......Page 285
A.3.2 Dielectric Electrostatic Shields......Page 289
A.3.3 Aperture Effects in Conductive Shields......Page 294
References......Page 296
Appendix B Magnetic Shielding......Page 297
B.1 Magnetic Shielding Mechanism......Page 298
B.2 Calculation Methods......Page 301
B.3.1 Spherical Magnetic Conducting Shield......Page 303
B.3.2 Cylindrical Magnetic Conducting Shield in a Transverse Magnetic Field......Page 308
B.3.3 Cylindrical Magnetic Conducting Shield in a Parallel Magnetic Field......Page 312
B.3.4 Infinite Plane......Page 316
References......Page 329
Appendix C Standards and Measurement Methods......Page 332
C.1 MIL-STD 285 and IEEE STD-299......Page 334
C.2 NSA 65-6 and NSA 94-106......Page 339
C.3 ASTM E1851......Page 340
C.4 ASTM D4935......Page 341
C.5 MIL-STD 461E......Page 343
C.6 Code of Federal Regulations, Title 47, Part 15......Page 350
C.7 ANSI\\SCTE 48-3......Page 352
C.8 MIL-STD 1377......Page 353
C.9 IEC Standards......Page 354
C.10 ITU-T Recommendations......Page 359
C.11 Automotive Standards......Page 361
References......Page 365
Index......Page 368