Millimeter-Wave Power Amplifiers (eBook)

Saurabh Sinha is full professor of Electronics at the University of Johannesburg, South Africa, where he has been Executive Dean of the Faculty of Engineering and Built Environment since 2013. In addition he is the managing editor of the South African Institute of Electrical Engineers (SAIEE) Africa Research Journal. 

Preface 6
Contents 9
Introduction 14
1 Power Amplifiers for Millimeter-Wave Systems 15
1.1 Overview of Power Amplifier Applications in Millimeter-Wave Bands 15
1.2 Power Amplifiers in Millimeter-Wave Transmitters 16
1.2.1 Sliding-IF Superheterodyne Transmitter Architecture 17
1.2.2 Direct Conversion Transmitter Architecture 18
1.3 Fundamental Parameters of Power Amplifiers 20
1.3.1 Gain 20
1.3.1.1 Basic Amplifier Gain Relationships 20
1.3.1.2 Two-Port Power Gains 22
1.3.1.3 Special Case Gain Expressions 25
1.3.1.4 Gain Flatness 26
1.3.2 Impedance Matching 26
1.3.2.1 Matching Topologies 27
1.3.2.2 Constant VSWR Design 28
1.3.2.3 Load-Pull Measurements 29
1.3.3 Stability 31
1.3.3.1 Conditional and Unconditional Stability 32
1.3.3.2 Testing for Unconditional Stability 32
1.3.4 Bandwidth 32
1.3.4.1 Broadband Techniques 33
1.3.5 Noise Figure 35
1.3.5.1 Amplifier Design for Minimal Noise Figure 35
1.3.5.2 Effects of Amplifier Mismatch 36
1.3.5.3 Noise Figure in a Cascaded System 37
1.3.6 Linearity 38
1.3.6.1 Gain Compression 39
1.3.6.2 Intermodulation and Harmonic Distortion 39
1.3.6.3 Amplifier Dynamic Range 42
1.3.7 Reverse Isolation 43
1.3.8 Output Power and Efficiency 43
1.4 Role of Electronic Design Automation in Power Amplifier Design 46
1.5 Content Overview 47
References 47
2 Systems Aspects of Millimeter-Wave Power Amplifiers 51
2.1 Antennas for Millimeter-Wave Applications 52
2.1.1 Antenna Parameters 52
2.1.1.1 Power Radiated by an Antenna 52
2.1.1.2 Antenna Directivity 54
2.1.1.3 Radiation Efficiency and Antenna Gain 55
2.1.1.4 Antenna Aperture Efficiency 56
2.1.2 Antenna Structures for Millimeter-Wave Systems 56
2.1.2.1 Slot Arrays 57
2.1.2.2 Integrated Horn Antennas 57
2.1.2.3 Conventional Printed Antennas 58
2.1.2.4 Surface Wave and Leaky Wave Antennas 59
2.1.2.5 Dielectric Resonator Antennas 60
2.2 Millimeter-Wave Wireless Communication Systems 60
2.2.1 The Friis Transmission Formula 61
2.2.2 Link Budget 62
2.2.3 Digital Modulation 64
2.2.3.1 Orthogonal Frequency Division Multiplexing 65
2.2.3.2 Constant Envelope Modulation 66
2.2.3.3 Single-Carrier Modulation Schemes 66
2.2.4 Wireless Communication Standards 67
2.2.5 Millimeter-Wave Cellular Networks 68
2.2.6 Wireless Communication Algorithms 69
2.2.6.1 Multiple Input, Multiple Output 69
2.2.6.2 Cooperative Communications 70
2.2.6.3 Dynamic Spectrum Access 71
2.3 Millimeter-Wave Radar 71
2.3.1 Radar Fundamentals 73
2.3.1.1 Radar Measurements 75
2.3.1.2 Radar Functions 79
2.3.1.3 Radar Resolution 81
2.3.2 Automotive Radar 82
2.3.2.1 Frequency Regulation 82
2.3.2.2 Classification of Automotive Radar Systems 84
2.3.3 Military Radar 84
2.4 Imaging 85
2.4.1 Millimeter-Wave Radiometry 86
2.4.2 Millimeter-Wave Imaging Systems 87
2.4.2.1 Aircraft Guidance Assistance 87
2.4.2.2 Airport Security 88
2.5 Closing Remarks 88
References 89
3 Technologies for Millimeter-Wave Power Amplifiers 93
3.1 The Importance of Silicon to Integrated Circuits 93
3.2 Bipolar Transistors 94
3.2.1 Operating Principles in the Forward-Active Mode 95
3.2.2 Frequency Limitations 98
3.2.2.1 Small-Signal Modeling 98
3.2.2.2 Transit Time 99
3.2.2.3 Cutoff Frequency 102
3.3 Heterojunction Bipolar Transistors 105
3.3.1 SiGe Epitaxy 107
3.3.2 HBT Figures of Merit 107
3.3.2.1 DC Characteristics 107
3.3.2.2 Frequency Response 109
3.3.2.3 Noise Performance 109
3.3.3 Vertical and Lateral Scaling 111
3.4 Field-Effect Transistors 112
3.4.1 Basic MOSFET Operation 113
3.4.2 High Frequency Performance 114
3.4.2.1 Small-Signal Modeling 115
3.4.3 CMOS for Millimeter-Wave Circuits 117
3.5 High Electron Mobility Transistors 118
3.6 Passive Components 119
3.6.1 On-Chip Inductors 120
3.6.2 Schottky Barrier Diodes 123
3.6.3 PIN Diodes 124
3.6.4 Through-Silicon via Technology 125
3.6.5 Capacitors 126
3.6.6 On-Chip Transmission Lines 126
3.7 System-on-Package Technology 128
3.8 Closing Remarks 129
References 129
Design Principles and State of the Art Review 134
4 Linear-Mode Millimeter-Wave Power Amplifiers 135
4.1 Analysis of Reduced Conduction Angle Waveforms 136
4.1.1 Drain Current 136
4.1.1.1 Constant Input Power 136
4.1.1.2 Variable Input Power 140
4.1.2 Shape Factor 142
4.1.3 Output Power 143
4.1.4 Loadline Resistance 144
4.1.5 Power Gain 144
4.2 Nonlinear Device Modeling and Performance 145
4.2.1 Device Operating Regions 146
4.2.2 Power-Added Efficiency 147
4.2.3 Small-Signal Intrinsic Modeling 148
4.2.4 Intrinsic Device Frequency Performance 149
4.2.5 MOSFET Layout Considerations 151
4.2.5.1 Gate Parameters 152
4.2.5.2 Source Parameters 152
4.2.5.3 Drain Parameters 153
4.2.6 Large-Signal Device Characterization and Operation 154
4.2.6.1 Device Limitations 154
4.2.6.2 Transistor Geometry 155
4.2.6.3 Loadline Resistance 156
4.2.6.4 Output Matching 156
4.3 Power Amplifier Classification 157
4.3.1 Modes of Operation 158
4.3.1.1 Class A 158
4.3.1.2 Class AB and B 161
4.3.1.3 Class C 164
4.3.2 Class A, AB, B and C Amplifier Topologies 166
4.3.2.1 Baseline Class A, AB, B and C Topology 166
4.3.2.2 Complementary Push-Pull Power Amplifiers 166
4.3.2.3 Transformer-Coupled Push-Pull Power Amplifiers 168
4.4 Closing Remarks 170
References 170
5 Millimeter-Wave Switching Mode Power Amplifiers 173
5.1 Fundamentals of Switching Mode Operation 174
5.1.1 Broadband Resistive Load 174
5.1.2 Tuned Load 178
5.2 Switching Mode Power Amplifier Classes 180
5.2.1 Comparison to Current-Source Amplifiers 180
5.2.2 Class D 182
5.2.3 Class E 184
5.2.3.1 Theory of Operation 185
5.2.3.2 Simple Bipolar Class E Amplifier Design 192
5.3 Switching Mode Amplifiers in Millimeter-Wave CMOS Technology 194
5.3.1 Parasitic Effects at Millimeter-Wave Frequencies 194
5.3.2 Improved Millimeter-Wave CMOS Class E Amplifier Design Methodology 195
5.3.2.1 Circuit Analysis 195
5.3.2.2 Parameter Optimization 198
5.4 Switching Mode Class E Amplifiers in SiGe HBT Technology 199
5.4.1 SiGe HBT Class E Amplifier Design Methodology for Millimeter-Wave Operation 199
5.4.2 Limitations on the Performance of Millimeter-Wave SiGe HBT Switching Amplifiers 203
5.4.3 Operating SiGe HBTs Beyond the {/varvec BV}_{{{/varvec CEO}}} Point 203
5.5 Transmitter Linearization Techniques for Switching Amplifiers 204
5.5.1 Outphasing Transmitters 204
5.5.2 Polar Transmitters 206
5.6 Concluding Remarks 207
References 207
6 Millimeter-Wave Stacked-Transistor Amplifiers 211
6.1 Stacking of FET Devices 212
6.1.1 Gate Capacitance {/varvec C}_{{/varvec N}} 213
6.1.2 Voltage Handling and Optimal Drain Impedance 215
6.1.3 Benefits and Challenges in Stacked Transistor Amplifier Design 218
6.2 Device Technology for Implementing Millimeter-Wave Stacked Amplifiers 219
6.3 Intermediate Node Matching 220
6.3.1 Determining the Optimal Complex Node Impedance 221
6.3.2 Effects of Phase Mismatch on Output Power and Efficiency 222
6.3.3 Matching for the Optimal Intermediate Node Impedance 223
6.3.3.1 Shunt Inductive Tuning 224
6.3.3.2 Series Inductive Tuning 225
6.3.3.3 Shunt Feedback Capacitive Tuning 226
6.4 Class E-like Stacked-Transistor Amplifiers 226
6.4.1 Switching FET Operation and Circuit Models 227
6.4.2 Analysis and Design of Millimeter-Wave Stacked-FET Class E-like Power Amplifiers 229
6.4.2.1 Methodology 229
6.4.2.2 Comparing Designs Through Waveform Figures of Merit 230
6.4.2.3 Active Drive Configurations 233
6.4.3 Analysis and Design of Millimeter-Wave Stacked-HBT Class E-like Power Amplifiers 233
6.4.3.1 Double Stack HBT Configuration 233
6.4.3.2 Triple Stack HBT Configuration 237
6.5 Multiple-Gate-Cell Stacked FET Amplifiers 241
6.5.1 Multiple-Gate-Cell Architecture 242
6.5.2 Design Concerns for Multiple-Gate FET Power Amplifiers 242
6.5.2.1 Interconnect Parasitics 242
6.5.2.2 Contact Parasitics 244
6.5.2.3 Thermal Design 244
6.5.2.4 Low-Q Gate Capacitance 245
6.6 Closing Remarks 245
References 246
7 Performance Enhancement Techniques for Millimeter-Wave Power Amplifiers 249
7.1 Improving Efficiency and Linearity 249
7.1.1 Fundamentals of Efficiency Improvement Techniques 249
7.1.2 Power Amplifier Linearization Techniques 253
7.1.2.1 Introduction to Linearization 254
7.1.2.2 An Overview of Predistortion Theory 255
7.1.2.3 Digital Predistortion 257
7.1.2.4 Introduction to Feedforward Techniques 258
7.1.2.5 Gain Compression in Feedforward Amplifiers 260
7.1.2.6 Output Coupler Influence on Feedforward Performance 261
7.1.2.7 Adaptive Feedforward Loops 262
7.1.2.8 Direct and Indirect Feedback Techniques 263
7.1.2.9 Cartesian Feedback 264
7.1.3 Doherty Amplifiers 267
7.1.3.1 Theory of Operation 267
7.1.3.2 Transformer-Based Doherty Power Amplifiers 275
7.1.3.3 Active Phase Shifting Doherty Power Amplifiers 276
7.1.3.4 Comparison of Millimeter-Wave Doherty Amplifiers 278
7.2 Improving Output Power 278
7.2.1 Performance Metrics of On-Chip Power Combining Techniques 279
7.2.1.1 Area Efficiency 279
7.2.1.2 Spatial Power Density 279
7.2.2 Planar Power Combining 280
7.2.2.1 Wilkinson Combiner 280
7.2.2.2 Capacitive Combiner 281
7.2.3 Transformer-Based Power Combining Techniques 288
7.2.3.1 Voltage-Combining Transformer 290
7.2.3.2 Current-Combining Transformer 292
7.2.3.3 Current-Voltage-Current Combining Transformer 294
7.2.3.4 Summary of Transformer-Based Combiner Networks 295
7.2.4 Three-Dimensional Power Combining 296
7.2.5 Spatial Power Combining 296
7.2.6 Comparison of Power Combining Amplifiers 297
7.3 Broadband Amplifiers and Bandwidth Improvement Techniques 297
7.3.1 Differential Amplifiers 298
7.3.2 Balanced Amplifiers 299
7.3.3 Distributed Amplifiers 300
7.3.3.1 Efficiency Limitations of Distributed Amplifiers 301
7.3.3.2 Supply Scaling in Distributed Amplifiers 304
7.3.3.3 Bandpass Distributed Amplifier Design Methodology 306
7.4 Closing Remarks 308
References 309
8 Architecture Considerations for Millimeter-Wave Power Amplifiers 316
8.1 Biasing of High-Frequency Power Transistors 316
8.1.1 Transistor Stability 316
8.1.2 Supply Modulation 319
8.1.3 Bias Network Design 319
8.1.4 Adaptive Biasing of CMOS Power Amplifiers 320
8.2 Millimeter-Wave Transmitter Architectures 321
8.2.1 Linear Transmitter Architectures 322
8.2.1.1 Doherty Amplifiers 323
8.2.2 Power-Combining Amplifiers 325
8.2.2.1 Performance Metrics of On-Chip Power Combining 326
8.2.2.2 Capacitive Combiners 327
8.2.2.3 Transformer-Coupled Power Combining 327
8.2.3 Outphasing Transmitters 329
8.2.3.1 Theory of Operation 331
8.2.3.2 Outphasing Signal Generation 332
8.2.3.3 Signal Combining 334
8.2.4 Polar Transmitters 337
8.2.4.1 Digital Polar Transmitters 338
8.2.5 Phased Array Transmitter Architectures 338
8.2.5.1 Transmitter Overview 338
8.2.5.2 Power Distribution 339
8.2.5.3 Bandwidth Limitations of Large Arrays 342
8.2.5.4 Phase Shifting 343
8.2.5.5 Amplitude Tapering in Non-Uniform Arrays 344
8.2.6 Sliding-IF Transmitters 346
8.2.7 Multistage Power Amplifiers 348
8.2.8 Push-Pull Techniques 349
8.3 Self-healing Techniques for Millimeter-Wave Power Amplifiers 350
8.3.1 Design Considerations for Self-healing System Components 352
8.3.1.1 Sensors 352
8.3.1.2 Control Actuators 353
8.3.1.3 Data Converters 353
8.3.1.4 DSP Core 354
8.3.2 Sensor Characteristics and Performance Metrics 354
8.3.2.1 Responsiveness and Latency 354
8.3.2.2 Noise and Sensitivity 355
8.3.2.3 Dynamic Range 355
8.3.2.4 Linearity and Monotonicity 355
8.3.2.5 Power and Performance Overhead 355
8.3.3 Sensor Measurements 356
8.3.3.1 DC Power and Efficiency 356
8.3.3.2 RF Power 356
8.3.3.3 Temperature 357
8.3.4 Processor Interface 358
8.3.4.1 Digitizing Analog Sensor Inputs 358
8.3.4.2 Generating Analog Actuator Inputs 358
8.3.5 Actuation Techniques 359
8.3.5.1 Actuators for Gate Bias Voltage Adjustment 359
8.3.5.2 Passive Network Tuning 359
8.3.5.3 Actuating the DC Supply and the Transistor Architecture 360
8.4 Concluding Remarks 360
References 361