Cover image for Introduction to modeling HBTs
Title:
Introduction to modeling HBTs
Personal Author:
Series:
Artech House microwave library
Publication Information:
Boston, MA : Artech House, 2006
ISBN:
9781580531443

Available:*

Library
Item Barcode
Call Number
Material Type
Item Category 1
Status
Searching...
30000010106360 TK7871.96.B55 R82 2006 Open Access Book Book
Searching...

On Order

Summary

Summary

Heterojunction bipolar transistors (HBTs) are a quite young technology and this book aims not only to give a reference of relevant HBT models, but also to discuss their background from a circuit-designer's point of view.


Author Notes

Matthias Rudolph is a senior scientist at the Ferdinand-Braun-Institut fur Hochstfrequenztechnik (FBH) in Berlin, Germany, where he is responsible for the characterization and modeling of FETs and HBTs for circuit design, and for the design of MMICs


Table of Contents

Prefacep. xiii
Chapter 1 Introductionp. 1
1.1 Heterojunction Bipolar Transistorsp. 1
1.2 Three Types of Models for Circuit Simulationp. 6
1.2.1 Physics-Based Modelsp. 6
1.2.2 Empirical Modelsp. 6
1.2.3 Table-Based Modelsp. 7
1.2.4 Comparison of the Modeling Approachesp. 8
1.3 Preconditions for Model Development and Usep. 10
1.4 The Model as a Nonlinear Circuitp. 11
1.5 Two Model Restrictions in Circuit Simulatorsp. 14
Referencesp. 19
Chapter 2 Compact Modeling Conceptsp. 21
2.1 Consistency of Large- and Small-Signal Modelsp. 21
2.1.1 Nonlinear Resistancesp. 22
2.1.2 Nonlinear Capacitancesp. 24
2.2 Numerical Considerationsp. 32
2.2.1 Definition Range, Derivatives, and Overflowp. 33
2.2.2 Asymptotic Correctnessp. 41
2.2.3 Unique Solutionp. 41
2.2.4 Model Parametersp. 43
2.2.5 Circuit Topologyp. 44
2.3 Dispersionp. 45
2.4 Calculating Self-Heating with a Circuit Simulatorp. 48
2.4.1 The Nonlinearity of the Thermal Resistancep. 50
2.5 Statistical Modelingp. 52
2.5.1 Types of Fluctuationsp. 52
2.5.2 Properties of Random Variablesp. 54
2.5.3 Objectives of a Statistical Modelp. 57
2.5.4 Principal Component Analysisp. 58
2.5.5 Physics-Based Statistical Modelingp. 60
2.5.6 Limitations of the Linear Approximationp. 62
Referencesp. 62
Chapter 3 HBT Physics and Technologyp. 65
3.1 Emitter-Base Junctionp. 65
3.1.1 DC Current at Low-Current Densitiesp. 65
3.1.2 Temperature Dependence of the Diode Currentp. 69
3.1.3 Recombination in the Space-Charge Regionp. 70
3.1.4 High-Current Densitiesp. 71
3.1.5 Injection Efficiencyp. 72
3.1.6 Heterojunctionp. 73
3.1.7 Stored Charges - Junction Capacitancesp. 75
3.2 Base Transportp. 79
3.2.1 Early Effectp. 82
3.2.2 Current Crowdingp. 83
3.3 Base-Collector Junctionp. 84
3.3.1 Collector Transit Time and Depletion Capacitancep. 84
3.3.2 High-Current Injectionp. 86
3.3.3 Avalanche Breakdownp. 95
3.3.4 Heterojunctionp. 98
3.4 HBT Technologyp. 99
Referencesp. 107
Chapter 4 Modeling of HBTsp. 109
4.1 The Equivalent Circuitp. 109
4.1.1 Ideal T- and Hybrid-[pi]-Topologies at DCp. 109
4.1.2 Nonideal Currents, Parasitic Elements, and Capacitancesp. 112
4.2 Basic Electrothermal Properties of HBTsp. 118
4.2.1 DC Properties of HBTsp. 118
4.2.2 The Gummel Plotp. 119
4.2.3 Output I/V Curvesp. 120
4.2.4 Transit Frequency and Maximum Frequency of Oscillationp. 124
4.2.5 The Typical Shape of HBT S-Parametersp. 128
4.3 The Gummel-Poon Charge-Control Relationp. 133
4.3.1 The Charge Function Q[subscript b]p. 136
4.4 Constant Time Delayp. 140
4.4.1 Base-Emitter Time Constantp. 141
4.4.2 Base-Collector Transcapacitancep. 143
4.4.3 Excess-Phase Networkp. 145
4.4.4 Transit-Time Approximations - [pi]-Topologyp. 147
4.4.5 Excess-Phase Network - [pi]-Topologyp. 148
4.4.6 Time Delay - [pi]-Topologyp. 150
4.5 Bias-Dependent Time Delayp. 151
4.6 Thermal Instabilitiesp. 156
4.6.1 Thermal Runawayp. 157
4.6.2 Numerical Instability Due to Self-Heatingp. 160
4.6.3 Distributed Thermal Effects and Hot Spotsp. 165
Referencesp. 173
Chapter 5 Noise Modelp. 175
5.1 Physical Noise Sourcesp. 175
5.1.1 The Link from Fluctuations in Time Domain to Noise Spectrap. 176
5.1.2 Thermal Noisep. 178
5.1.3 Shot Noisep. 180
5.1.4 Diffusion Noisep. 180
5.1.5 Low-Frequency Noisep. 182
5.2 Noise Sources at Large-Signal Excitationp. 184
5.3 Noise Calculation with Correlation Matricesp. 186
5.4 HBT Noise Modelp. 190
5.4.1 Shot Noisep. 190
5.4.2 Thermal Noisep. 196
5.4.3 Complete White Noise Modelp. 196
5.4.4 1/f Noisep. 201
Referencesp. 205
Chapter 6 HBT Modelsp. 207
6.1 The SPICE Gummel-Poon Modelp. 208
6.1.1 DC Modelp. 208
6.1.2 Capacitances and Transit Timesp. 211
6.1.3 Substrate Capacitancep. 212
6.1.4 Temperature Scalingp. 212
6.1.5 Area Scalingp. 214
6.1.6 Noise Modelp. 214
6.2 The VBIC Modelp. 216
6.2.1 Basic Transistor Isothermal DC Operation and Breakdownp. 217
6.2.2 Capacitances and Transit Timesp. 220
6.2.3 Quasi-Saturation Modelp. 222
6.2.4 Substrate Transistorp. 223
6.2.5 Self-Heatingp. 225
6.2.6 Noise Modelp. 228
6.3 The UCSD HBT Modelp. 232
6.3.1 DC Modelp. 233
6.3.2 The Depletion Capacitancesp. 235
6.3.3 The Forward Diffusion Chargep. 236
6.3.4 The Substrate Branchp. 244
6.3.5 Thermal Modelp. 245
6.3.6 Noise Modelp. 247
6.4 The Agilent HBT Modelp. 250
6.4.1 DC Modelp. 252
6.4.2 The Depletion Capacitancesp. 253
6.4.3 The Diffusion Capacitances and Transit-Time Modelp. 254
6.4.4 Resistances and Extrinsic Parametersp. 257
6.4.5 Thermal Modelp. 257
6.4.6 Noise Modelp. 260
6.5 The FBH HBT Modelp. 263
6.5.1 DC Modelp. 264
6.5.2 The Depletion Capacitancesp. 267
6.5.3 Base-Collector Capacitance and Transit Timesp. 268
6.5.4 Resistances and Extrinsic Parametersp. 271
6.5.5 Thermal Modelp. 272
6.5.6 Model Scalingp. 273
6.5.7 Noise Modelp. 273
Referencesp. 276
Chapter 7 Measurement and Parameter Extractionp. 279
7.1 General Considerationsp. 280
7.1.1 Systematic Sources of Extraction Uncertaintyp. 280
7.1.2 Influence of Measurement Equipmentp. 284
7.1.3 Choosing the Right Devicep. 284
7.2 Deembedding Techniques - Extrinsic Parametersp. 285
7.2.1 Deembedding from Test-Structure Measurements and EM Simulationp. 286
7.2.2 Determining R[subscript e] and R[subscript c] from DC Measurementsp. 289
7.2.3 Determining Extrinsic Elements from S-Parameter Measurementsp. 290
7.3 Intrinsic Small-Signal Parametersp. 294
7.3.1 Extraction of R[subscript b2] and C[subscript ex]p. 295
7.3.2 Extracting the Other Parametersp. 297
7.4 Thermal Resistance and Time Constantsp. 298
7.4.1 Thermal Resistancep. 298
7.4.2 Thermal Time Constantsp. 306
7.5 Large-Signal Model Parametersp. 308
7.5.1 DC Parametersp. 308
7.5.2 Charge Functionsp. 311
7.6 Model Verificationp. 313
Referencesp. 314
About the Authorp. 317
Indexp. 319