Wireless LAN Radios

Arya Behzad is currently a Broadcom Distinguished Engineer, where he is the Director of Engineering working on radios for current and future generation wireless products and Product Line Manager for all wireless LAN radio products. This book and his IEEE Expert Now course on wireless LAN radio design are both derived from his popular course on this topic at the IEEE ISSCC.

• Preface ixAcronyms xiCHAPTER 1 802.11 Flavors and System Requirements 11.1 Definition 11.2 WLAN Market Trends 31.3 History of 802.11 61.4 802.11: b, a, or g? 81.5 802.11b Standard 101.6 802.11a Channel Allocation 131.7 802.11a and 802.11g: OFDM Mapping 141.7.1 Multipath Fading 141.8 802.11a/g: Data Rates 211.9 802.11a/g OFDM Packet Construction 241.10 802.11 System Requirements 241.10.1 Receiver Sensitivity 241.10.2 Transmitter Error Vector Magnitude 261.10.3 Transmitter Spectral Mask 281.11 Vector Signal Analysis 33CHAPTER 2 Radio Receiver and Transmitter Architectures 432.1 Architectures 432.1.1 Superheterodyne Receiver 442.1.1.1 Choice of Intermediate Frequency in Superheterodyne Receiver 472.1.2 Low IF Receiver 512.1.3 Direct-Conversion Receiver 552.1.4 Receiver Architectures: Summary 592.1.5 Superheterodyne Transmitter 602.1.6 Low IF Transmitter 642.1.7 Direct-Conversion Transmitter 642.1.8 Polar Modulators 662.2 Process Choices: CMOS versus SiGe BiCMOS 67CHAPTER 3 Analog Impairments and Issues 733.1 Receiver Sensitivity and Noise Figure 733.2 Receiver DC Offsets and LO Leakage 753.3 Receiver Flicker Noise 793.4 Receiver Interferers and Intermodulation Distortion 833.4.1 IP3, IP2, and P1dB 833.4.2 Tools for Analyzing Modulated Signal Distortion 963.5 Receiver Image Rejection 1023.5.1 Superheterodyne Receiver 1023.5.2 Low IF Architecture 1043.5.3 Direct-Conversion Receiver 1063.6 Quadrature Balance and Relation to Image Rejection 1073.7 Quadrature Balance and Relation to EVM 1093.8 Other Transmitter (Modulator) Impairments 1163.9 Peak-to-Average Ratio and Relation to Linearity and Efficiency 1213.10 Local Oscillator Pulling in PLL 1243.11 Phase Noise in PLL 1263.12 Far-Out Phase Noise 1303.13 Effect of Phase Noise on OFDM Systems 1313.14 Effect of Frequency Errors on OFDM 1323.15 Summary of Analog/RF Impairments 135CHAPTER 4 Some Key Radio Building Blocks 1374.1 Low Noise Amplifier 1374.2 Mixer and its Local Oscillator Buffers 1424.3 Power Amplifier 1484.4 Fully Integrated VCO 1534.5 Multifrequency (Stacked) Mixer 1574.6 Open-Loop Transconductance Linearization Circuit 158CHAPTER 5 Calibration Techniques 1615.1 VCO Calibration 1635.2 Automatic Frequency Control 1655.3 Quadrature Error and Local Oscillator Feedthrough Calibration 1725.4 Bias Current Calibrations (R Calibration) 1755.5 Filter Time-Constant Calibration (RC Calibration) 1765.6 Other Calibrations 177CHAPTER 6 Case Studies 1796.1 Case Study 1: A CMOS 802.11a Transceiver 1796.1.1 Architecture and Circuit Implementation 1796.1.2 Receiver 1816.1.3 Transmitter 1836.1.4 Phase-Locked Loop 1866.2 Case Study 2: High Performance WLAN Transmitter Utilizing Quadrature and LOFT Calibration 189CHAPTER 7 Brief Discussion Of 802.11n and Concluding Remarks 1977.1 Need for 802.11n 1977.2 802.11a/b/g/n MIMO Transceiver 2027.2.1 Architecture and Circuit Implementation 2037.2.1.1 Receiver 2037.2.1.2 Transmitter 2057.2.1.3 PLL and LO Generation 2077.2.1.4 Calibration Techniques 2097.2.2 Packaging Issues 2117.2.3 Measurement Results 2117.2.4 MIMO Case Study Conclusion 2167.3 Concluding Remarks 217References 221Annotated Bibliography 223Index 233About the Author 241