应用电磁学基础 2001年多媒体版 英文本PDF电子书下载

1 INTRODUCTION:WAVES AND PHASORS 1

1-1 Dimensions,Units,and Notation 4

1-2 The Nature of Electromagnetism 5

1-2.1 The Gravitational Force:A Useful Analogue 6

1-2.2 Electric Fields 7

1-2.3 Magnetic Fields 9

1-2.4 Static and Dynamic Fields 11

1-3 Traveling Waves 12

1-3.1 Sinusoidal Wave in a Lossless Medium 14

1-3.2 Sinusoidal Wave in a Lossy Medium 17

1-4 The Electromagnetic Spectrum 19

1-5 Review of Complex Numbers 22

1-6 Review of Phasors 24

Problems 29

2 TRANSMISSION LINES 33

2-1 General Considerations 35

2-1.1 The Role of Wavelength 36

2-1.2 Propagation Modes 37

2-2 Lumped-Element Model 39

2-3 Transmission-Line Equations 43

2-4 Wave Propagation on a Transmission Line 44

2-5 The Lossless Transmission Line 47

2-5.1 Voltage Reflection Coefficient 48

2-5.2 Standing Waves 51

2-6 Input Impedance of the Lossless Line 55

2-7.1 Short-Circuited Line 58

2-7 Special Cases of the Lossless Line 58

2-7.2 Open-Circuited Line 60

2-7.3 Application of Short-Circuit and Open-Circuit Measurements 60

2-7.4 Lines of Length ι=nλ/2 62

2-7.5 Quarter-Wave Transformer 62

2-7.6 Matched Transmission Line:Z8L=Z0 62

2-8 Power Flow on a Lossless Transmission Line 64

2-8.1 Instantaneous Power 64

2-8.2 Time-Average Power 65

2-9 The Smith Chart 66

2-9.1 Parametric Equations 66

2-9.2 Input Impedance 71

2-9.3 SWR,Voltage Maxima and Minima 73

2-9.4 Impedance to Admittance Transformations 74

2-10 Impedance Matching 80

2-11 Transients on Transmission Lines 84

2-11.1 Transient Response 84

2-11.2 Bounce Diagrams 88

Problems 92

3 VECTOR ANALYSIS 100

3-1 Basic Laws of Vector Algebra 101

3-1.1 Equality of Two Vectors 102

3-1.2 Vector Addition and Subtraction 103

3-1.3 Position and Distance Vectors 103

3-1.4 Vector Multiplication 104

3-1.5 Scalar and Vector Triple Products 107

3-2 Orthogonal Coordinate Systems 108

3-2.2 Cylindrical Coordinates 109

3-2.1 Cartesian Coordinates 109

3-2.3 Spherical Coordinates 113

3-3 Transformations between Coordinate Systems 115

3-3.1 Cartesian to Cylindrical Transformations 115

3-3.2 Cartesian to Spherical Transformations 117

3-3.3 Cylindrical to Spherical Transformations 119

3-3.4 Distance between Two Points 119

3-4 Gradient of a Scalar Field 120

3-4.1 Gradient Operator in Cylindrical and Spherical Coordinates 121

3-4.2 Properties of the Gradient Operator 122

3-5 Divergence of a Vector Field 123

3-5.1 Divergence Theorem 125

3-5.2 Remarks on Notation 125

3-6 Curl of a Vector Field 127

3-6.1 Vector Identities Involving the Curl 128

3-6.2 Stokes's Theorem 129

3-7 Laplacian Operator 130

Problems 132

4 ELECTROSTATICS 138

4-1 Maxwell's Equations 139

4-2 Charge and Current Distributions 140

4-2.1 Charge Densities 140

4-2.2 Current Density 142

4-3 Coulomb's Law 143

4-3.1 Electric Field due to Multiple Point Charges 144

4-3.2 Electric Field due to a Charge Distribution 145

4-5.4 Electric Field as a Function of Electric Potential 147

4-4 Gauss's Law 148

4-5 Electric Scalar Potential 151

4-5.1 Electric Potential as a Function of Electric Field 151

4-5.2 Electric Potential due to Point Charges 153

4-5.3 Electric Potential due to Continuous Distributions 153

4-5.5 Poisson's Equation 155

4-6 Electrical Properties of Materials 156

4-7 Conductors 157

4-7.1 Resistance 158

4-7.2 Joule's Law 160

4-8 Dielectrics 161

4-9 Electric Boundary Conditions 163

4-9.1 Dielectric—Conductor Boundary 166

4-9.2 Conductor—Conductor Boundary 167

4-10 Capacitance 168

4-11 Electrostatic Potential Energy 172

4-12 Image Method 173

Problems 176

5 MAGNETOSTATICS 186

5-1 Magnetic Forces and Torques 187

5-1.1 Magnetic Force on a Current-Carrying Conductor 189

5-1.2 Magnetic Torque on a Current-Carrying Loop 192

5-2 The Biot—Savart Law 195

5-2.1 Magnetic Field due to Surface and Volume Current Distributions 196

5-2.2 Magnetic Field of a Magnetic Dipole 199

5-3 Magnetic Force between Two Parallel Conductors 200

5-4 Maxwell's Magnetostatic Equations 201

5-4.1 Gauss's Law for Magnetism 201

5-4.2 Amphere's Law 202

5-5 Vector Magnetic Potential 206

5-6 Magnetic Properties of Materials 208

5-6.1 Orbital and Spin Magnetic Moments 208

5-6.2 Magnetic Permeability 209

5-6.3 Magnetic Hysteresis of Ferromagnetic Materials 210

5-7 Magnetic Boundary Conditions 213

5-8 Inductance 214

5-8.1 Magnetic Field in a Solenoid 215

5-8.2 Self-inductance 216

5-8.3 Mutual Inductance 218

5-9 Magnetic Energy 219

Problems 221

6 MAXWELL'S EQUATIONS FOR TIME-VARYING FIELDS 229

6-1 Faraday's Law 231

6-2 Stationary Loop in a Time-Varying Magnetic Field 233

6-3 The Ideal Transformer 237

6-4 Moving Conductor in a Static Magnetic Field 238

6-5 The Electromagnetic Generator 241

6-6 Moving Conductor in a Time-Varying Magnetic Field 243

6-7 Displacement Current 244

6-8 Boundary Conditions for Electromagnetics 246

6-9 Charge-Current Continuity Relation 247

6-10 Free-Charge Dissipation in a Conductor 249

6-11 Electromagnetic Potentials 250

6-11.1 Retarded Potentials 250

6-11.2 Time-Harmonic Potentials 251

Problems 255

7 PLANE-WAVE PROPAGATION 260

7-1 Time-Harmonic Fields 262

7-1.1 Complex Permittivity 263

7-1.2 Wave Equations for a Charge-Free Medium 263

7-2 Plane-Wave Propagation in Lossless Media 264

7-2.1 Uniform Plane Waves 264

7-2.2 General Relation between E and H 268

7-3 Wave Polarization 269

7-3.1 Linear Polarization 270

7-3.2 Circular Polarization 271

7-3.3 Elliptical Polarization 273

7-4 Plane-Wave Propagation in Lossy Media 276

7-4.1 Low-Loss Dielectric 278

7-4.2 Good Conductor 278

7-5 Current Flow in a Good Conductor 280

7-6 Electromagnetic Power Density 283

7-6.1 Plane Wave in a Lossless Medium 284

7-6.2 Plane Wave in a Lossy Medium 285

7-6.3 Decibel Scale for Power Ratios 286

Problems 288

8 WAVE REFLECTION AND TRANSMISSION,AND GEOMETRIC OPTICS 292

8-1 Wave Reflection and Transmission at Normal Incidence 294

8-1.1 Boundary between Lossless Media 294

8-1.2 Transmission-Line Analogue 297

8-1.3 Power Flow in Lossless Media 298

8-1.4 Boundary between Lossy Media 301

8-2 Snell's Laws 303

8-3 Fiber Optics 306

8-4 Wave Reflection and Transmission at Oblique Incidence 308

8-4.1 Perpendicular Polarization 309

8-4.2 Parallel Polarization 313

8-4.3 Brewster Angle 315

8-5 Reflectivity and Transmissivity 316

8-6 Geometric Optics 319

8-7 Images Formed by Mirrors 320

8-7.1 Images Formed by Plane Mirrors 321

8-7.2 Images Formed by Spherical Mirrors 322

8-8 Images Formed by Spherical Lenses 324

Problems 332

9 RADIATION AND ANTENNAS 340

9-1 The Short Dipole 343

9-1.1 Far-Field Approximation 345

9-1.2 Power Density 346

9-2 Antenna Radiation Characteristics 348

9-2.1 Antenna Pattern 349

9-2.2 Beam Dimensions 351

9-2.3 Antenna Directivity 351

9-2.4 Antenna Gain 354

9-2.5 Radiation Resistance 354

9-3 Half-Wave Dipole Antenna 355

9-3.1 Directivity of λ/2 Dipole 357

9-3.2 Radiation Resistance of λ/2 Dipole 357

9-3.3 Quarter-Wave Monopole Antenna 358

9-4 Dipole of Arbitrary Length 359

9-5 Effective Area of a Receiving Antenna 360

9-6 Friis Transmission Formula 363

9-7 Radiation by Large-Aperture Antennas 365

9-8 Rectangular Aperture with Uniform Aperture Distribution 368

9-8.1 Beamwidth 369

9-8.2 Directivity and Effective Area 370

9-9 Antenna Arrays 371

9-10 N-Element Array with Uniform Phase Distribution 378

9-11 Electronic Scanning of Arrays 380

9-11.1 Uniform-Amplitude Excitation 382

9-11.2 Array Feeding 382

Problems 386

10 SATELLITE COMMUNICATION SYSTEMS AND RADAR SENSORS 390

10-1 Satellite Communication Systems 391

10-2 Satellite Transponders 393

10-3 Communication-Link Power Budget 396

10-4 Antenna Beams 398

10-5.1 Basic Operation of a Radar System 399

10-5 Radar Sensors 399

10-5.2 Unambiguous Range 400

10-5.3 Range and Angular Resolutions 401

10-6 Target Detection 402

10-7 Doppler Radar 404

10-8 Monopulse Radar 406

Problems 410

APPENDIX A SYMBOLS,QUANTITIES,AND UNITS 411

APPENDIX B MATERIAL CONSTANTS OF SOME COMMON MATERIALS 413

APPENDIX C MATHEMATICAL FORMULAS 415

APPENDIX D ANSWERS TO ODD-NUMBERED PROBLEMS 417

BIBLIOGRAPHY 423

INDEX 425