Acknowledgments xvii
1 Linear RF amplifier design— general considerations 1
1.1 Introduction 1
1.2 Power gain definitions 3
1.3 Neutralization 7
1.4 Unilateral transducer gain 8
1.4.1 Unilateral figure of merit 10
1.4.2 Illustrative example: unilateral gain calculations 12
1.4.3 Amplifier design with single matching networks 13
1.4.4 Unilateral constant gain circles 15
1.4.5 Illustrative example: single-sided amplifier design 15
1.5 RF circuit stability considerations 19
1.5.1 What may cause RF oscillation 22
1.5.2 Stability analysis with arbitrary source and load terminations 25
1.5.3 Two-port stability considerations 30
1.5.4 Stability circles 35
1.5.5 Graphical forms of unconditional stability 40
1.5.6 Graphical forms of potential instability 41
1.5.7 Caution about multistage systems 42
1.6 Stabilizing an active two-port 46
1.6.1 Finding the minimum-loss resistor at the input of the device 47
1.6.2 Broadband stability considerations 49
1.7 Stabilization of a bipolar transistor 50
1.7.1 Examining the effect of lossless feedback 50
1.7.2 Device stabilization 51
1.8 The dc bias techniques 59
1.8.1 Passive dc bias networks 60
1.8.2 Active dc bias circuits 63
1.8.3 Feeding dc bias into the RF circuit 64
1.8.4 The dc bias circuit simulation 65
1.8.5 Filtering of dc bias networks 69
1.9 Statistical and worst-case analyses 69

1.10 Circuit layout considerations 71
1.11 Summary 74
1.12 Problems 74
References 75
Selected bibliography 76
2 Linear and low-noise RF amplifiers 77
2.1 Introduction 77
2.2 Bilateral RF amplifier design for maximum small-signal gain 78
2.2.1 Illustrative exercise: amplifier design for maximum gain, GMAX 82
2.3 Multistage amplifiers 88
2.3.1 Cascading impedance-matched stages 88
2.3.2 Cascading amplifiers by direct impedance matching 89
2.3.3 Output power and impedance match considerations of
cascaded amplifiers 92
2.4 Operating gain design for maximum linear output power 94
2.4.1 Operating gain design outline 95
2.4.2 GP versus POUT trade-offs 97
2.4.3 Stability considerations 97
2.4.4 Illustrative example: operating gain design for maximum
linear power output 98
2.4.5 Output match considerations 101
2.5 Noise in RF circuits 102
2.5.1 Review of noise sources in RF systems 102
2.5.2 Two-port noise parameter definitions 106
2.6 Available gain design technique 107
2.6.1 Available gain design outline 108
2.6.2 Low-noise amplifier design considerations 110
2.6.3 Illustrative example: design of a single-ended 1.9-GHz LNA 111
2.6.4 Balanced amplifiers 114
2.6.5 Illustrative example: design of a balanced LNA for the 1.7-
to 2.3-GHz frequency range 116
2.7 Comparison of the various amplifier designs and Smith chart–
based graphical design aids 121
2.8 Broadband amplifiers 123
2.8.1 Reactive match/mismatch approach 124
2.8.2 Dissipative mismatch at input and/or output ports 125
2.8.3 Amplifier-equalizer combinations 129
2.8.4 Feedback amplifiers 129
2.8.5 Distributed amplifiers 141
2.9 Summary 142
2.10 Problems 143
References 144
Selected bibliography 145