RF与无线技术精要

Part 1 Fundamentals 3

1 Basic Concepts 3

Introduction 4

Vocabulary 5

Prefixes 6

Basic Electronics Terminology 6

RF Basics 7

Transmitters and Receivers 7

Signals 8

2 RF Behavior 15

Loss and Gain 16

Devices 16

Attenuation 17

Insertion Loss 18

Decibels 19

Definition 19

Decibel Math 19

Bandwidth 22

Definition 22

RF in the Environment 24

Signal Behavior 24

Wideband and Narrowband 24

Match 28

What Is Match? 28

Consequences of an Imperfect Match 30

Part 2 RF Hardware 35

3 Basic System Components 35

Block Diagrams 36

Receiver 37

Transmitter 37

Antennas 38

Block Diagram 38

Antenna Characteristics 39

How Antennas Work 42

Antenna Performance 43

Polarization 45

Antenna Dimensions 46

Smart Antennas 48

Amplifiers 49

Block Diagram 49

Fundamental Properties of Amplifiers 49

HowAmplifiers Work 54

Special Amplifiers 55

Block Diagram 57

Filters 57

The Filter's Function 58

FilterTypes 59

Filter Performance 59

Special Filters 61

Mixers 63

Block Diagram 63

The Mixer's Function 64

HoW Mixers Work 65

Mixer Configurations 67

Block Diagram 68

Sources 68

How Oscillators Work 69

Different Kinds of Oscillators 70

A Special Oscillator-The VCO 71

Synthesizers 72

A Quick Review 73

Transmitter Block Diagram 74

Receiver Block Diagram 74

Review 75

4 Other Components 77

Switch Function and Performance 79

Block Diagram 79

Switches 79

Types of Switches 80

System Use 83

Attenuators 84

Block Diagram 84

The Attenuator's Function 84

Types of Attenuators 85

Dividers and Combiners 88

Block Diagram 88

The Dividers'and Combiners'Functions 88

System Use 89

Couplers 90

Block Diagram 90

How Couplers Work 90

Types of Couplers 91

Circulators and Isolators 93

Block Diagram 93

How Circulators Work 93

System Use 94

Isolators 95

Block Diagram 96

The Transformer's Function 96

Transformers 96

Detectors 98

Block Diagram 98

The Detector's Function 98

Phase Shifters 99

Block Diagram 99

The Phase Shifter's Function 99

Phase Detectors 100

The Phase Detector's Function 100

Review of Components 101

5 Circuits and Signa？s 103

Semiconductors 104

Materials and Devices 104

Diodes 107

Transistors 107

Integrated Circuits(MMIC) 110

Circuit Technologies 111

Lumped and Distributed Circuits 111

Discrete,Hybrid,and MMIC Circuit Choices 114

Subassemblies 117

Cavities 117

What Is Modulation? 119

Modulation 119

Types of Modulation 120

Modulators and Demodulators 127

Getting Around 128

Cables 128

Connectors 131

Waveguides 134

Circuit Traces 135

Part 3 RF Systems 141

6 Older Technology 141

What Is Broadcasting? 143

Broadcasting 143

The Role of Frequency 145

Tuning In 148

Television Delivery 149

Radar 153

What Is Radar? 153

HowRadarWorks 155

Different Radar Systems 159

Satellite Communications 162

Why Satellites? 162

How Satellites Work 164

Satellite Systems 171

A Special Satellite System-GPS 174

The Next Generation Satellites-LEO 179

The Internet from Above 181

Point-to-Point Microwave 187

What Is Point-to-Point Microwave? 187

Point-to-Point Operations 188

7 Mobile Telephony 191

A World of Choices 193

Differentiators 193

Worldwide Systems 194

Topology 195

The Cellular Concept 195

Infrastructure 197

Mobility 198

Adding Capacity 199

Underlying Technology 201

Frequency Reuse 201

Air Interface 203

Cellular Phone Block Diagram 206

CDMA Explained 209

Spread Spectrum 209

Channels 217

Different Generations 218

Cellular Evolution 218

Paths of Migration to 3G 221

8 The New World of Wireless 225

Broadband Fixed Wireless 227

Wireless Local Loop 227

Air Link Transmission Technologies 236

Wireless Networks 240

Local Area Networks 240

Personal Area Networks 247

Home Networks 249

The Mobile Internet 252

Technology 253

M-Commerce 255

The Bleeding Edge 256

Up-and-Coming Technologies 257

Security Issues 263

Health Concerns 266

Glossary 269

Appendix A-Acronyms 283

Appendix B-Specifications 293

Bibliography 297

About the Author 299

Index 301