WIRELESS TRANSCEIVER DESIGN Mastering the Design of Modern Wireiess Equipment and Systems

Ariel Luzzatto and Gadi Shirazi

B I C I N T I N H I A l

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B I C I N T I N N I A L

John Wiley & Sons, Ltd

Contents

Preface xiii About the Authors xvii Abbreviations xix

1 Modern Transceiver Architectures 1 1.1 Overview 1 1.2 Receiver Architectures 2

1.2.1 Superheterodyne Receiver (SHR) 3 1.2.1.1 SHR Highlights 3 1.2.1.2 Quadrature (IQ) Modulation Highlights 6 1.2.1.3 SHR Outlook 12

1.2.2 Direct Conversion Receiver (DCR) 12 1.2.2.1 DCR Highlights 13 1.2.2.2 DCR Outlook 13

1.2.3 Very Low IF Receiver (VLIF) 14 1.2.3.1 VLIF Highlights 14 1.2.3.2 Complex Polyphase Filter Highlights 15 1.2.3.3 VLIF Outlook 18

1.3 Transmitter Architectures 18 1.3.1 Two-Step Conversion Transmitter (TSCT) 19

1.3.1.1 TSCT Highlights 20 1.3.1.2 TSCT Outlook 20

1.3.2 Direct Launch Transmitter (DLT) 21 1.3.2.1 DLT Highlights 21 1.3.2.2 DLT Outlook 22

1.3.3 Direct FM Transmitter (DFMT) 22 1.3.3.1 DFMT Highlights 23 1.3.3.2 DFMT Outlook 24

1.3.4 Dual-Port Direct FM Transmitter (DDFMT) 24 1.3.4.1 DDFMT Highlights 24 1.3.4.2 DDFMT Outlook 25

viii Contents

1.4 Transceiver Architectures 25 1.4.1 Full-Duplex CDMA/FDMA Architectures 26

1.4.1.1 Full-Duplex Highlights 27 1.4.1.2 Full-Duplex Outlook 28

1.4.2 Half-Duplex/TDMA Architectures 28 1.4.2.1 Half-Duplex Highlights 30 1.4.2.2 Half-Duplex Outlook 30

1.4.3 Simplex/TDD Architectures 30 1.4.3.1 Simplex Highlights 32 1.4.3.2 Simplex Outlook 32

1.4.4 Ultra-Wideband (UWB) Systems 32

2 Receiving Systems 35 2.1 Sensitivity 35

2.1.1 Computation of Sensitivity 36 2.1.1.1 Computation of SHR Sensitivity 36 2.1.1.2 Computation of DCR Sensitivity 38 2.1.1.3 Computation of VLIF Sensitivity 39

2.1.2 Measurement of Sensitivity 39 2.2 Co-Channel Rejection 40

2.2.1 Computation of Co-Channel Rejection 41 2.2.2 Measurement of Co-Channel Rejection 41

2.3 Selectivity 42 2.3.1 Computation of Selectivity 43

2.3.1.1 Computation of SHR Selectivity 46 2.3.1.2 Computation of DCR Selectivity 47 2.3.1.3 Computation of VLIF Selectivity 48

2.3.2 Measurement of Selectivity 49 2.4 Intermodulation Rejection 49

2.4.1 Computation of Intermodulation Rejection 50 2.4.2 Measurement of Intermodulation Rejection 51

2.5 Half-IF Rejection 53 2.5.1 Computation of Half-IF Rejection 54 2.5.2 Measurement of Half-IF Rejection 55

2.6 Image Rejection 56 2.6.1 Computation of Image Rejection 57 2.6.2 Measurement of Image Rejection 57

2.7 Second-Order Distortion Rejection 58 2.7.1 Computation of Second-Order Distortion Rejection 58 2.7.2 Measurement of Second-Order Distortion Rejection 59

Contents ix

2.8 Blocking 59 2.8.1 Computation of Blocking 60 2.8.2 Measurement of Blocking 61

2.9 Dynamic Range 61 2.9.1 Computation of Dynamic Range 62 2.9.2 Measurement of Dynamic Range 62

2.10 Duplex Desense 62 2.10.1 Computation of Duplex Desense 63 2.10.2 Measurement of Duplex Desense 64

2.11 Duplex-Image Rejection 65 2.11.1 Computation of Duplex-Image Rejection 65 2.11.2 Measurement of Duplex-Image Rejection 67

2.12 Half-Duplex Spur 68 2.13 Phantom-Duplex Spurs 68 2.14 Conducted and Radiated Spurs 69

3 Transmitting Systems 71 3.1 Peak-to-Average Power Ratio (PAPR) 72

3.1.1 Computation of PAPR for Quasi-Static RF Signals 72 3.1.2 Measurement of PAPR 77

3.2 Effects of Nonlinearity in RF Power Amplifiers 77 3.2.1 Analytic Models for PA Nonlinearity 78 3.2.2 Effects of PA Nonlinearity on Digital Modulation 82 3.2.3 Effects of PA Nonlinearity on Spectral Shape 83 3.2.4 A Tight Bound for Spectral Regrowth 88

3.3 Characterization of PA Nonlinearity 92 3.3.1 Intermodulation Distortion (IMD) 95

3.3.1.1 Measurement of IMDN 99 3.3.2 Error Vector Magnitude (EVM) 100

3.3.2.1 Measurement of EVM 102 3.3.3 Adjacent Coupled Power Ratio (ACPR) 103

3.3.3.1 Measurement of ACPR 104 3.3.4 Spectral Mask 104

3.3.4.1 Measurement of Spectral Mask 105 3.4 PA Efficiency 105 3.5 Transmitter Transients 106

3.5.1 AttackTime 107 3.5.2 Frequency Shift Upon Keying 107

3.6 Conducted and Radiated Emission 108 3.6.1 Conducted Spurs 108

Contents

3.6.2 Back Intermodulation 109 3.6.3 Radiated Spurs 110

3.6.3.1 Radiation Basics 110 3.6.3.2 Antenna Aperture 111 3.6.3.3 Measurement of Radiated Spurs 112

3.7 Enhancement Techniques 113 3.7.1 Linearization Techniques 114

3.7.1.1 Cartesian Feedback 114 3.7.1.2 Feed-forward 116 3.7.1.3 Pre-distortion 118

3.7.2 Envelope-Tracking Supply 118

4 Synthesizers 121 4.1 Synthesizer Architectures 121 4.2 Fractional-N Outlook 123 4.3 Fractional-7V Theory 124

4.3.1 Dual-Count Fractional-N 126 4.3.2 First-Order Sigma-Delta Fractional-N 126

4.4 Multi Stage Noise Shaping (MASH) Architecture 129 4.4.1 Stage One 130 4.4.2 Stage Two 131 4.4.3 Stage Three 134

4.5 MASH Noise Analysis 135 4.5.1 Pseudorandom Sequence Bounds 142

4.6 Analog Sigma-Delta A/D Converter 144 4.7 Review of PLL Fundamentals 147

4.7.1 Basic Integer-N Configuration 148 4.7.2 Integer-N Transient Analysis 150 4.7.3 Integer-N Lock Time Analysis 158 4.7.4 Phase-Frequency Detector 161

4.8 Extension of PLL Fundamentals to Fractional-A^ 162 4.9 Measurement of Synthesizers 165

4.9.1 Lock Time 166 4.9.2 Frequency Accuracy and Stability 168 4.9.3 Reference Spurs 168

5 Oscillators 169 5.1 Low-Power Self-Limiting Oscillators 170 5.2 Feedback Network Design 172 5.3 Noisy Oscillator - Leeson's Equation 175 5.4 Bipolar Oscillators 181

5.4.1 Non-Saturating Bipolar Theory 181

Contents xi

5.4.2 Detailed Bipolar VCO Design 185 5.5 Crystal Oscillators 201

5.5.1 Piezoelectric Crystal Outlook 201 5.5.2 Fundamental-Mode Inverter-Driven Oscillators 202

5.6 Measurement of Crystal Parameters 208 5.7 Measurement of Oscillators 210

5.7.1 Phase Noise as Narrowband FM 211 5.7.2 Single Sideband (SSB) Noise 212 5.7.3 Residual FM 216 5.7.4 Frequency Pushing/Pulling 218 5.7.5 Output Flatness 219

5.8 Lumped Equivalent of Distributed Resonators 219 5.8.1 Resonant Low-Loss Transmission Lines 220

5.9 Harmonie Oscillators 224 5.10 A Unified Approach to Oscillator Design 225

6 Parasitic and Nonlinear Phenomena 227 6.1 Parasitic Effects in Oscillators and Synthesizers 227

6.1.1 Injection Locking 228 6.1.2 Injection Pulling 230 6.1.3 Remodulation 230 6.1.4 Reverse Junction Breakdown 231 6.1.5 Microphonics 232 6.1.6 Ground Currents 232 6.1.7 Parasitic Poles and PLL Stability 234

6.1.7.1 Perturbative Analysis 235 6.2 Intercept Point and Spurious Responses 239

6.2.1 Receiver Intermodulation Rejection (IMRN) 242 6.2.2 Transmitter Intermodulation Distortion (IMDN) 244 6.2.3 Measurement of Input Intercept Points (IPNi) 247

6.3 Parasitic Effects in Transmitters 247 6.3.1 PA Instability 248 6.3.2 Spectral 'Bumps' 249

6.4 Parasitic Effects in Receivers 251 6.4.1 Able-Baker Spurs 252 6.4.2 Self-Quieters 252 6.4.3 Doppler Blocking 254 6.4.4 Chopper Noise 254

6.5 Specific Absorption Rate (SAR) 255

Bibliography Index

257 261