Modeling and design techniques for RF power amplifiers The book covers RF power amplifier design from device and modeling considerations to advanced circuit design architectures and techniques. It focuses on recent developments and advanced topics in this area including numerous practical designs to back the theoretical considerations. It presents the challenges in designing power amplifiers in silicon and helps the reader improve the efficiency of linear power amplifiers and design more accurate compact device models with faster extraction routines to create cost effective and reliable circuits 4.2.4 Modified BSIM3v3 Model 116 4.3 Summary 120 References 120 5 POWER AMPLIFIEIR IC DESIGN 123 5.1 Introduction 123 5.2 Power Amplifier Design Methodology 124 5.3 Classes of Operation 125 5.4 Performance Metrics 132 5.5 Thermal Instability and Ballasting 136 References 138 6 POWER AMPLIFIER DESIGN IN SILICON 141 6.1 Introduction 141 6.2 A 2.4 GHz High Efficiency SiGe HBT Power Amplifier 142 6.2.1 Circuit Design Considerations 143 6.2.2 Analysis of Ballasting for SiGe HBT Power Amplifiers 146 6.2.3 Harmonic Suppression Filter and Output Match Network 148 6.2.4 Performance of the Power Amplifier Module 150 6.3 RF Power Amplifier Design Using Device Periphery Adjustment 153 6.3.1 Analysis of the Device Periphery Adjustment Technique 155 6.3.2 1.9 GHz CMOS Power Amplifier 157 6.3.3 1.9 GHz CDMA PCS SiGe HBT Power Amplifier 162 6.3.4 Nonlinear Term Cancellation for Linearity Improvement 166 References 169 7 EFFICIENCY ENHANCEMENT OF RF POWER AMPLIFIERS 173 7.1 Introduction 173 7.2 Efficiency Enhancement Techniques 174 7.2.1 Envelope Elimination and Restoration 174 7.2.2 Bias Adaptation 175 7.2.3 The Doherty Amplifier Technique 175 7.2.4 Chireixs Outphasing Amplifier Technique 176 7.3 The Classical Doherty Amplifier 179 7.4 The Multistage Doherty Amplifier 181 7.4.1 Principle of Operation 181 7.4.2 Analysis of Efficiency 186 7.4.3 Practical Considerations 188 7.4.4 Measurement Results 190 References 198 INDEX 199 PREFACE ix 1 INTRODUCTION 1 1.1 Semiconductor Technology and RF Power Amplifier Design 2 1.2 Device Modeling 3 1.3 Power Amplifier IC Design 4 1.4 Power Amplifier Linearity 5 1.5 Modulation Schemes 5 1.6 Circuit Simulation 9 1.7 Load Pull Measurements 10 References 13 2 DEVICE MODELING FOR CAD 15 2.1 Introduction 15 2.2 Bipolar Junction and Weterojunction Bipolar Transistors 16 2.3 Bipolar Device Models 18 2.3.1 The Ebers Moll Model 18 2.3.2 The Gummel Poon Model 20 2.3.3 The VBlC Model 25 2.3.4 MEXTRAM 29 2.3.5 HICUM 32 2.4 MOSFET Device Physics 35 2.5 MOSFET Device Models 38 2.5.1 The Level 1 Model 38 2.5.2 The Level 2 and Level 3 Models 40 2.5.3 BSlM 40 2.5.4 The BSIM2 and HSPICE Level 28 Models 43 2.5.5 BSIM3 44 2.5.6 MOS Model 9 and MOS Model 11 45 2.5.7 BSIM4 45 References 46 3 EMPIRICAL MODELING OF BIPOLAR DEVICES 49 3.1 Introduction 49 3.1.1 Modeling the HBT versus the BJT 49 3.1.2 Parameter Extraction 50 3.1.3 Motivation for an Empirical Bipolar Device Model 51 3.1.4 Physics Based and Empirical Models 53 3.1.5 Compatibility between Large and Small Signal Models 53 3.2 Model Construction and Parameter Extraction 54 3.2.1 Current Source Model 54 3.2.2 Current Source Model Parameter Extraction 56 3.2.3 Extraction of Intrinsic Capacitances 58 3.2.4 Extraction of Base Resistance 60 3.2.5 Parameter Extraction Procedure 61 3.3 Temperature Dependent InGaP GaAs HBT Large Signal Model 63 3.4 Empirical Si BJT Large Signal Model 71 3.5 Extension of the Empirical Modeling Method to the SiGe HBT 77 3.6 Summary 83 References 83 4 SCALABLE MODELING OF RF MOSFETS 87 4.1 Introduction 87 4.1.1 NQS Effects 88 4.1.2 Distributed Gate Resistance 89 4.1.3 Distributed Substrate Resistance 89 4.2 Scalable Modified BSIM3v3 Model 91 4.2.1 Scalability of MOSFET Model 91 4.2.2 Extraction of Small Signal Model Parameters 94 4.2.3 Scalable Substrate Network Modeling 101