Preface to the First Edition ................................ ix
Preface to the Second Edition ............................. xiii
Preface to the Third Edition .............................. xyii
1 Introduction ................................................. 1
1.1 Introduction and Historical Perspective ................. 1
1.2 Personal Communications ................................. 3
1.3 Electromagnetics Fundamentals ........................... 5
1.3.1 Maxwell's Equations .............................. 8
1.3.2 Boundary Conditions ............................. 10
1.3.3 Vector and Scalar Potentials .................... 11
1.3.4 Radiation from a Sinusoidally Excited Current
Element ......................................... 12
1.3.5 Duality in Maxwell's Equations .................. 14
1.3.6 Current Loop for Sinusoidal Excitation .......... 16
1.3.7 Radiation of a UWB Elementary Dipole and Loop ... 16
1.3.8 Radiation Zones ................................. 20
1.4 Basic Radiowave and Antenna Parameters ................. 23
1.5 Summary ................................................ 30
Problems .................................................... 30
References .................................................. 35
2 Fixed-Site Antennas ......................................... 37
2.1 Introduction ........................................... 37
2.2 Antennas as Arrays of Current Sources .................. 39
2.3 Pattern Multiplication and Array Factor ................ 39
2.4 Collinear Antennas and Vertical-Plane Pattern
Control ................................................ 40
2.5 Directivity and Beam Width for Omnidirectional
Antennas ............................................... 41
2.6 Array Antennas ......................................... 42
2.6.1 Collinear Array and Fourier Transform ........... 43
2.6.2 Horizontal-Plane Pattern Directivity ............ 44
2.6.3 Aperture Antennas: Two-Dimensional Transforms ... 45
2.7 Pattern Shaping of High-Gain Collinear Antennas ........ 46
2.8 Multiple-Beam Antennas ................................. 49
2.8.1 Matrix-Fed Multiple-Beam Antenna Designs ........ 50
2.8.2 Smart Antennas .................................. 51
2.9 Proximity Effects in Antennas .......................... 53
2.9.1 Treating Scatterers as Infinitely Long
Cylinders ....................................... 53
2.9.2 Modeling the Finite-Length Scatterer ............ 55
2.9.3 Measured and Calculated Patterns Involving
Cylindrical Scatterers .......................... 57
2.9.4 Application to an Antenna Mounted on the Side
of a Tower ...................................... 57
2.9.5 Effect of Antenna Distortion on Coverage
Range ........................................... 61
2.9.6 Parasitically Driven Array Antennas ............. 61
2.10 Indoor Fixed Sites ..................................... 65
2.10.1 Wireless Local-Area Network Fixed Sites ......... 66
2.10.2 Gain Antennas for UWB Pulses .................... 66
2.11 Summary ............................................... 68
Problems .................................................... 69
References .................................................. 73
3 Radio Communication Channel ................................. 77
3.1 Introduction ........................................... 77
3.2 Guided Waves ........................................... 78
3.2.1 Losses in Dielectrics ........................... 78
3.2.2 Losses in Conductors ............................ 80
3.2.3 Coaxial Transmission Lines ...................... 81
3.2.4 Parallel Transmission Lines ..................... 84
3.2.5 Minimum Attenuation in Transmission Lines ....... 85
3.2.6 Summary of Transmission Line Relationships ...... 86
3.2.7 Optical Fiber Transmission Lines ................ 86
3.3 Basic Radiowave Propagation ............................ 87
3.3.1 Friis Transmission Formula ...................... 88
3.3.2 Comparison of Guided Wave and Radiowave
Propagation Attenuation ......................... 89
3.4 Wave Polarization ...................................... 90
3.4.1 Polarization of Antennas ........................ 90
3.4.2 Polarization Characteristics of Antennas ........ 91
3.4.3 Polarization Mismatch in Antennas ............... 91
3.4.4 Polarization Filtering: An Experiment in
Optics .......................................... 92
3.4.5 Polarization Scattering and the Radar
Equation ........................................ 93
3.5 Summary ................................................ 94
Problems .................................................... 95
References .................................................. 98
4 Radio Frequency Spectrum .................................... 99
4.1 Introduction ........................................... 99
4.2 Extremely Low and Very Low Frequencies (<30 kHz) ...... 101
4.3 Low and Medium Frequencies (30 kHz to 3 MHz) .......... 103
4.4 High Frequencies (3 to 30 MHz) ........................ 103
4.4.1 Ionosphere ..................................... 104
4.4.2 Layers in the Ionosphere ....................... 104
4.4.3 Ionized Gases .................................. 105
4.4.4 Ionospheric Reflection ......................... 106
4.4.5 Maximum Usable Frequency ....................... 106
4.4.6 Multiple Hops in Shortwave Communications ...... 107
4.5 Very High Frequencies and Ultrahigh Frequencies
(30 MHz to 3 GHz) ..................................... 110
4.5.1 Communications via Scattering from Meteor
Trails ......................................... 110
4.5.2 Propagation by Tropospheric Bending ............ 113
4.5.3 Tropospheric Scattering ........................ 113
4.6 Above Ultrahigh Frequencies (Above 3 GHz) ............. 114
4.7 Picking an Optimum Operating Frequency ................ 114
4.8 Multiuser Communications Systems ...................... 117
4.8.1 Paging Systems ................................. 118
4.8.2 Digital Voice Broadcasting Systems ............. 122
4.8.3 Packet Access Systems .......................... 123
4.8.4 Cellular and Mobile Voice Systems .............. 125
4.8.5 Third-Generation Voice and Data Mobile
Systems ........................................ 129
4.8.6 Broadband Wireless Access Systems .............. 131
4.8.7 Wireless Local-Area Network Systems ............ 132
4.8.8 UWB Systems .................................... 134
4.9 Summary ............................................... 135
Problems ................................................... 136
References ................................................. 141
5 Communications Using Earth-Orbiting Satellites ............. 145
5.1 Introduction .......................................... 145
5.2 Satellite Orbit Fundamentals .......................... 146
5.2.1 Orbital Mechanics .............................. 146
5.2.2 Orbital Predictions ............................ 148
5.2.3 Types of Orbits ................................ 149
5.2.4 Big LEO Systems ................................ 151
5.3 Satellite Propagation Path ............................ 151
5.3.1 Path Loss in a Satellite Link .................. 152
5.3.2 Doppler Shift .................................. 154
5.3.3 Coverage from Satellites ....................... 155
5.3.4 Link Characteristics from Earth-Orbiting
Satellites ..................................... 157
5.4 Polarization Effects in Signals from an Orbiting
Satellite ............................................. 160
5.4.1 Effects of Reflections and Diffractions ........ 160
5.4.2 Faraday Rotation of Polarization ............... 161
5.5 Summary ............................................... 163
Problems ................................................... 164
References ................................................. 169
6 Radiowave Propagation over a Smooth Earth .................. 171
6.1 Introduction .......................................... 171
6.2 A Two-Ray Propagation Model for Harmonic Waves ........ 171
6.2.1 Spherical Wave with Modifiers .................. 172
6.2.2 Plane Wave Reflection Coefficients ............. 174
6.2.3 Two-Layer Ground Model ......................... 175
6.2.4 Surface Wave Factor ............................ 176
6.2.5 Grazing Angle of Incidence ..................... 177
6.3 An Open-Field Test Range Model ........................ 178
6.3.1 A Two-Ray Model of an Open-Field Test Site ..... 180
6.3.2 Field Strength Versus Ground Parameters ........ 181
6.3.3 Field-Strength Profile on a 45m Range .......... 182
6.3.4 Calibrating a Test Site ........................ 183
6.3.5 Effect of the Calibration Gain Standard ........ 185
6.4 UWB Pulse Propagation with a Ground Reflection ........ 187
6.4.1 UWB Pulse in Free Space ........................ 187
6.4.2 Ground Reflection with a UWB Pulse ............. 190
6.4.3 UWB Pulses Sent at High Repetition Rate ........ 193
6.5 Summary ............................................... 194
Problems ................................................... 194
References ................................................. 197
7 Radiowave Propagation: Urban and Suburban Paths ............ 199
7.1 Introduction .......................................... 199
7.2 Theoretical Models for Urban Propagation .............. 200
7.2.1 Diffracting Screens Model ...................... 200
7.2.2 COST Model ..................................... 205
7.2.3 Diffraction over Knife-Edge Obstacles .......... 206
7.3 Empirical Models for Urban Propagation ................ 208
7.3.1 Okumura Signal Prediction Method ............... 208
7.3.2 Hata and Modified Hata Formulas ................ 208
7.3.3 Ibrahim and Parsons Method: London Model ....... 212
7.4 Propagation beyond the Horizon ........................ 214
7.5 Propagation within, near, and into Buildings .......... 216
7.5.1 Theoretical In-Building Multipath-Based
Model .......................................... 216
7.5.2 Theoretical In-Building Ray-Tracing Model ...... 217
7.5.3 An In-Room Deterministic Propagation Model ..... 218
7.5.4 Propagation near Buildings ..................... 221
7.5.5 Propagation into Buildings ..................... 223
7.6 Polarization Effects .................................. 224
7.6.1 Polarization Cross-Coupling Model Using
Diffraction .................................... 225
7.6.2 An Urban Model of Polarization Cross-
Coupling ....................................... 227
7.6.3 Polarization Cross-Coupling Measurements ....... 229
7.6.4 A Three-Dimensional Model of Incident Waves .... 231
7.7 Summary ............................................... 231
Problems ................................................... 232
References ................................................. 235
8 Signals in Multipath Propagation ........................... 239
8.1 Introduction .......................................... 239
8.2 Urban Propagation: Understanding Signal Behavior ...... 241
8.3 Statistical Descriptions of Signals ................... 242
8.3.1 Multipath and Fading: Local Variations ......... 243
8.3.2 Large-Scale Signal Variations .................. 246
8.3.3 Combining Cumulative Distribution Functions .... 247
8.3.4 Normal Approximation to Composite CDF .......... 248
8.3.5 Small-Scale Signal Variations and Delay
Spread ......................................... 248
8.3.6 Multipath with UWB Pulses ...................... 251
8.3.7 Relation Between Multipath and Propagation
Law ............................................ 252
8.4 Signal Strength Required for Communications ........... 254
8.4.1 Signal Call Success Probability ................ 255
8.4.2 Determining the Fixed Station Power ............ 257
8.5 Diversity Techniques .................................. 258
8.5.1 Diversity Improvement by Repeated
Transmission ................................... 258
8.5.2 Simultaneous Transmissions in Radio
Communications ................................. 259
8.5.3 Diversity Reception by Multiple Antennas ....... 263
8.5.4 Diversity Reception of Lognormally
Distributed Signals ............................ 266
8.5.5 Diversity Reception of Rayleigh-Distributed
Signals ........................................ 268
8.5.6 Mitigation of Multipath Effects ................ 270
8.5.7 Maximum Rake Gain for UWB Pulses in
Multipath ...................................... 271
8.6 Multiple-Input, Multiple-Output Systems ............... 271
8.6.1 A MIMO System Reference Model .................. 271
8.6.2 MIMO System Capacity ........................... 273
8.6.3 MIMO System Capacity with a LOS Component ...... 273
8.7 Summary ............................................... 274
Problems ................................................... 275
References ................................................. 278
9 Receiver Sensitivity and Transmitted Fields ................ 281
9.1 Introduction .......................................... 281
9.2 Field-Strength Sensitivity of Receivers ............... 282
9.2.1 Statistical Method for Measuring Field-
Strength Sensitivity ........................... 282
9.2.2 Determining the 80% Calling Response Rate ...... 283
9.2.3 Accuracy ofthe20-Call Test ..................... 284
9.2.4 A Simplified Three-of-Three Method ............. 285
9.3 Relating Field Strength to Received Power ............. 286
9.3.1 Pattern Gain Averaging ......................... 287
9.3.2 Averaging Methods for Mobile Phone Testing ..... 289
9.4 Test Site Field-Strength Calibration .................. 290
9.5 Reliability and Repeatability of Sensitivity
Measurements .......................................... 291
9.5.1 Repeatability of Sensitivity Measurements ...... 292
9.5.2 Variations in the Calibration Factor Due to
Ground Parameters .............................. 293
9.5.3 Field-Strength Variations with Height .......... 293
9.5.4 Accuracy of the Calibration Gain Standards ..... 294
9.5.5 Intercomparison of Receiver-Sensitivity Test
Sites .......................................... 295
9.5.6 Test Range Error Uncertainties ................. 297
9.6 EMC and EMI Test Chamber .............................. 300
9.7 Transmitter Test Sites ................................ 301
9.8 Effect of the Human Body .............................. 302
9.8.1 Fields External to the Body .................... 302
9.8.2 Biological Aspects ............................. 303
9.9 RF Exposure Standards ................................. 305
9.9.1 Radiated RF Exposure Guidelines and
Regulations .................................... 306
9.9.2 Compliance with RF Exposure Standards .......... 309
9.10 Influence of Ground on Yagi Antenna Patterns .......... 313
9.11 Summary ............................................... 316
Problems ................................................... 316
References ................................................. 319
10 Simulated Human Body Devices ............................... 323
10.1 Introduction .......................................... 323
10.2 Field-Strength Sensitivities of Body-Worn Receivers ... 324
10.2.1 Population Sample for Measurements ............. 325
10.2.2 Design of the Measurement Experiment ........... 326
10.2.3 Receiver-Sensitivity Measurement Results ....... 327
10.3 Analysis of Phantom Simulated Human Body Devices ...... 330
10.3.1 Saline Water ................................... 331
10.3.2 SALTY and SALTY-LITE Human Body Devices ........ 334
10.3.3 Lossy Wire Antenna Model of Simulated Body
Devices ........................................ 334
10.3.4 Infinite Cylinder Model of Simulated Body
Devices for Vertical Polarization .............. 337
10.3.5 Infinite Cylinder Model of Simulated Body
Devices for Horizontal Polarization ............ 340
10.4 Magnetic Fields Around Simulated Body Devices ......... 341
10.4.1 Temperature Dependence of Simulated Body
Devices ........................................ 341
10.4.2 Measured and Computed Fields near the
Simulated Body Devices ......................... 342
10.4.3 Body Enhancement in Body-Worn Receivers ........ 344
10.5 Anthropomorphic Simulated Head ........................ 345
10.6 Summary ............................................... 346
Problems ................................................... 347
References ................................................. 348
11 Loops, Dipoles, and Patch Antennas ......................... 351
11.1 Introduction .......................................... 351
11.2 A Look at Quality Factor Q ............................ 351
11.2.1 Definition of Q ................................ 352
11.2.2 Values of Q .................................... 354
11.3 Primer on Fundamental Limitations in Small Antenna .... 355
11.3.1 Fields of Radiating Structures ................. 355
11.3.2 Modal Impedances of Free Space Modes ........... 355
11.3.3 Quality Factors Qn of Free Space Modes ......... 357
11.3.4 Small Antenna Bandwidth Limitations ............ 359
11.3.5 Superdirectivity in Small Antennas ............. 360
11.4 Antennas for Personal Communications .................. 361
11.4.1 Loops and Their Characteristics ................ 361
11.4.2 Gap-Fed Loop ................................... 364
11.4.3 Near Fields of an Elementary Loop .............. 365
11.4.4 Dipoles and Their Characteristics .............. 366
11.4.5 Near Fields of Dipoles ......................... 367
11.4.6 A Ferrite-Loaded Loop Antenna .................. 369
11.5 Transmission Line Antennas ............................ 370
11.5.1 Rectangular Microstrip Patch Antennas .......... 371
11.5.2 Circular Microstrip Patch Antennas ............. 375
11.6 Practical Considerations in Small Antennas ....... 378
11.6.1 Helix-Radio Dipole ............................. 379
11.6.2 Mutual Coupling of a Dipole with a Radio
Case ........................................... 381
11.7 UWB Antennas .......................................... 384
11.7.1 Radiation of Short Pulses ...................... 384
11.7.2 Far-Field of an Arbitrary UWB Antenna .......... 386
11.7.3 Receiving UWB Signals .......................... 388
11.8 A Simple UWB Antenna .................................. 390
11.9 Summary ............................................... 392
Problems ................................................... 394
References ................................................. 397
12 Radio Communications System Designs ........................ 401
12.1 Introduction .......................................... 401
12.2 Noise ................................................. 402
12.2.1 Thermal Noise .................................. 402
12.2.2 Noise and Noise Temperature in the Radio
Spectrum ....................................... 403
12.2.3 Noise Asymmetry in Two-Way and Mobile
Systems ........................................ 406
12.3 Designing a Messaging System Downlink ................. 406
12.3.1 Fixed-Site Antenna Radiation Patterns .......... 407
12.3.2 Applying the Statistical Description of
Waves .......................................... 409
12.3.3 Link Margins for Specified Performance ......... 410
12.3.4 Simulcast Differential Delay ................... 413
12.4 Designing Two-Way Systems ............................. 416
12.4.1 Two-Way Paging System .......................... 416
12.4.2 Mobile/Cellular System ......................... 417
12.5 Indoor Systems ........................................ 418
12.5.1 Wireless Local-Area Networks ................... 418
12.5.2 Wireless Personal-Area Networks ................ 419
12.6 System Coverage ....................................... 419
12.6.1 Coverage Probability over an Area .............. 421
12.6.2 Proving Measurements ........................... 422
12.7 Summary ............................................... 424
Problems ................................................... 424
References ................................................. 427
Appendix A: FORTRAN Programs: The Near Field of Dipoles
and Helices ............................................. 429
References .............................................. 431
Appendix B: FORTRAN Code: The Near Field of Loops .......... 433
References .............................................. 435
Appendix C: Digital Communications Codes and Character
Sets .................................................... 437
Morse Code .............................................. 437
Digital Paging Codes .................................... 438
Appendix D: HF Propagation Models .......................... 443
VOACAP, ICEPAC, REC533 .................................. 444
HamCAP .................................................. 444
About the Authors .......................................... 447
List of Symbols ............................................ 449
Vector quantities .......................................... 452
Index ...................................................... 455
|
