RF Power Amplifiers for Wireless Communications Second Edition Steve C. Cripps ARTECH HOUSE BOSTON LONDON artechhouse.com
Contents Preface to the Second Edition CHAPTER 1 1.1 1.2 Linear RF Amplifier Theory 1.3 Weakly Nonlinear Effects: Power and Volterra Series 1.4 Strongly Nonlinear Effects 1.5 Nonlinear Device Models for CAD 1.6 Conjugate Match 1.7 RF Power Device Technology CHAPTER 2 Linear Power Amplifier Design 2.1 Class A Amplifiers and Linear Amplifiers 2.2 Gain Match and Power Match 2.3 to Load-Pull Measurements 2.4 Loadline Theory 2.5 Package Effects and Refinements to Load-Pull Theory 2.6 Drawing the Load-Pull Contours on CAD Programs 2.7 Class A Design Example 2.8 Conclusions : CHAPTER 3 Conventional High Efficiency Amplifier Modes 3.1 3.2 Reduced Conduction Angle Waveform Analysis 3.3 Output Termination 3.4 Reduced Conduction Angle Mode Analysis FET Model Case 1: Class A Case 2: Class AB Case 3: Class B Case 4: Class C 3.5 Reduced Conduction Angle Mode Analysis BJT Model 3.6 Effect of I-V "Knee" 3.7 Input Drive Requirements xi 1 1 2 5 6 9 11 14 15 17 17 19 20 21 27 31 31 36 37 39 39 40 43 47 48 49 51 53 55 59 61 V
VI Contents 3.8 Conclusions CHAPTER 4 Class AB PAs at GHz Frequencies 4.1 4.2 Class AB Using a Capacitive Harmonic Termination The Class J PA 4.2.1 Theory 4.2.2 Practicalities 4.3 Nonlinear Device Characteristics 4.4 Nonlinear Capacitance Effects in RF Power Devices 4.4.1 4.4.2 Nonlinear Capacitors Characterization and Analysis 4.4.3 Input Varactor Effects on Class AB PAs 4.5 Conclusions CHAPTER 5 Practical Design of Linear RF Power Amplifiers 5.1 Low-Pass Matching Networks 5.2 Transmission Line Matching 5.3 Shorting the Harmonics 5.4 A Generic MESFET 5.5 A 2W Class B Design for 850 MHz 5.6 The Pi Section Power Matching Network 5.7 Pi Section Analysis for PA Design 5.8 Class J Design Example 5.9 HBT Design Example 5.10 Conclusions CHAPTER 6 Overdriven PAs and the Class F Mode 6.1 6.2 Overdriven Class A Amplifier 6.3 Overdriven Class AB Amplifier 6.4 Class F: and Theory 6.5 Class F in Practice 6.6 The Clipping Model for the Class F Mode Class FD 6.7 PA_Waves 6.8 Class F Simulations 6.9 Conclusions CHAPTER 7 Switching Mode Amplifiers for RF Applications 7.1 65 65 67 67 68 68 73 77 81 81 81 84 89 89 91 92 100 102 105 107 112 115 122 124 129 131 133 133 134 139 143 149 155 163 164 171 172 173 173
Contents VII 7.2 A Simple Switching Amplifier 7.3 A Tuned Switching Amplifier 7.4 The Class D Switching Amplifier 7.4 Class E 7.5 Class E Simplified Analysis 7.6 Class E Design Example 7.7 Conclusions CHAPTER 8 Switching PA Modes at GHz Frequencies 8.1 8.2 Ignoring the Obvious: Breaking the 100% Barrier 8.3 Waveform Engineering 8.4 PA_Waves 8.5 Implementation and Simulation 8.6 Conclusions CHAPTER 9 Nonlinear Effects in RF Power Amplifiers 9.1 9.2 Two-Carrier Power Series Analysis 9.3 Two-Carrier Envelope Analysis 9.4 Envelope Analysis with Variable PAR 9.5 AM to PM Effects 9.6 PA Memory Effects 9.7 Digital Modulation Systems 9.7.1 to Digital Modulation 9.7.2 QPSK Modulation Systems 9.7.3 CDMA and WCDMA 9.7.4 OFDM Modulation, 802.11/16 Standards 9.8 30 Watt LDMOS Test Amplifier Measurements 9.9 Conclusions CHAPTER 10 Efficiency Enhancement Techniques 10.1 Efficiency Enhancement 10.2 The Doherty Amplifier 10.3 Realization of the Doherty Amplifier 10.4 Outphasing Techniques 10.5 Envelope Elimination and Restoration (EER) 10.6 Envelope Tracking 10.7 Power Converters for EER and ET 10.8 Pulse Width Modulation (PWM) 174 178 180 182 183 192 198 199 201 201 202 205 216 225 227 229 231 231 233 240 246 250 256 261 261 262 268 275 278 282 283 285 285 286 290 298 303 309 311 314 318
VIII Contents 10.9 Other Efficiency Enhancement Techniques 10.9.1 The Sequential Power Amplifier 10.9.2 Pulse Position Modulation 10.9.3 RF to DC Conversion 10.9.4 RF Switching Techniques 10.9.5 Smart Antennas 10.10 Case Studies in Efficiency Enhancement 10.11 Conclusions CHAPTER 11 Power Amplifier Bias Circuit Design 11.1 11.2 Stability of RF Power Transistors 11.3 Bias Supply Modulation Effects 11.4 Bias Network Design 11.5 Bias Insertion Networks 11.6 Prime Power Supply Issues 11.7 Bias Control Circuits 11.8 Conclusions CHAPTER 12 Load-Pull Techniques 12.1 Tuner Design for Fundamental Load-Pull 12.2 Harmonic Load-Pull 12.3 Active Harmonic Load-Pull 12.4 Variations, Results, Conclusions CHAPTER 13 Power Amplifier Architecture 13.1 Push-Pull Amplifiers 13.2 Balanced Amplifiers 13.3 Power Combining 13.4 Multistage PA Design 13.5 Conclusions CHAPTER 14 Power Amplifier Linearization Techniques 14.1 to PA Linearization 14.2 Predistortion 14.2.1 to Predistortion Theory 14.2.2 Digital Predistortion (DPD) 323 323 325 326 328 329 330 333 334 337 337 338 343 350 353 354 355 356 357 359 359 362 365 367 369 371 371 372 380 387 391 394 395 397 397 399 401 401 404
Contents ix 14.2.3 Analog Predistortion 14.2.4 Predistortion Conclusions 14.3 Feedforward Techniques 14.3.1 Feedforward, 14.3.2 Feedforward Gain Compression 14.3.3 Feedforward Effect of the Output Coupler 14.3.4 Feedforward Adaptive Controls 14.3.5 Feedforward Practical Issues, Conclusions 14.4 Feedback Techniques 14.4.1, Direct Feedback Techniques 14.4.2 Indirect Feedback Techniques 14.4.3 The Cartesian Loop 14.4.4 The Polar Loop 14.5 Other Linearization Methods 14.6 Conclusions APPENDIX A PA Waves APPENDIX B Spectral Analysis Using Excel IQ Spreadsheets Bibliography Introductory Texts on RF and Microwave Techniques Wireless Communications Digital Modulation Nonlinear Techniques and Modeling Power Amplifier Techniques Recommended Reading Glossary About the Author Index 407 410 410 410 411 414 417 418 419 419 420 421 423 424 425 426 429 433 436 437 441 443