Adaptive RF Front-Ends for Hand-held Applications (eBook)

Andre van Bezooijen, Reza Mahmoudi, Arthur H.M. van Roermund (Autoren)

eBook Download: PDF

2010 | 2011
XV, 153 Seiten
Springer Netherland (Verlag)
978-90-481-9935-8 (ISBN)

Infos

The RF front-end - antenna combination is a vital part of a mobile phone because its performance is very relevant to the link quality between hand-set and cellular network base-stations. The RF front-end performance suffers from changes in operating environment, like hand-effects, that are often unpredictable.

Adaptive RF Front-Ends for Hand-Held Applications presents an analysis on the impact of fluctuating environmental parameters. In order to overcome undesired behavior two different adaptive control methods are treated that make RF frond-ends more resilient: adaptive impedance control, and adaptive power control.

Several adaptive impedance control techniques are discussed, using a priori knowledge on matching network properties, in order to simplify robust 2-dimensional control. A generic protection concept is presented, based on adaptive power control, which improves the ruggedness of a power amplifier or preserves its linearity under extremes. It comprises over-voltage, over-temperature, and under-voltage protection.

Inhalt

Contents 6
Abbreviations 10
Symbols 12
Chapter 1: Introduction 18
1.1 Context and Trends in Wireless Communication 18
1.2 Resilience to Unpredictably Changing Environments 19
1.3 Improvements by Adaptively Controlled RF Front-Ends 21
1.4 Aim and Scope of This Book 22
1.5 Book Outline 24
Chapter 2: Adaptive RF Front-Ends 26
2.1 Introduction 26
2.2 RF Front-End Functionality 27
2.2.1 Antenna Switch 27
2.2.2 Power Amplifier 28
2.2.3 Duplexer 30
2.2.4 Blocking Filter 31
2.3 Fluctuations in Operating Conditions 31
2.4 Impact of Variables 33
2.4.1 Current Fluctuation 33
2.4.2 Voltage Fluctuation 35
2.4.3 Die Temperature Fluctuation 38
2.4.4 Efficiency Fluctuation 39
2.4.5 Discussion on the Impact of Variables 41
2.5 Adaptive Control Theory 42
2.6 Identification of Variables for Detection and Correction 44
2.6.1 Independent Variables 45
2.6.2 Dependent Variables 46
2.6.2.1 Singly Dependent Variables 46
2.6.2.2 Multiply Dependent Variables 46
Detection 47
Actuation of Multiply Dependent Variables 48
Actuation of Singly Dependent Variables 49
2.7 Conclusions on Adaptive RF Front-Ends 49
Chapter 3: Adaptive Impedance Control 51
3.1 Introduction 51
3.1.1 Dimensionality 53
3.1.2 Non-linearity 55
3.1.3 Robust Control 57
3.1.4 Impedance Tuning Region 61
3.1.5 Insertion Loss 63
3.1.6 System Gain 64
3.2 Mismatch Detection Method 65
3.2.1 Sensing 65
3.2.2 Detector Concept 66
3.2.3 Simulation Results 67
3.2.4 Conclusions on Mismatch Detection 68
3.3 Adaptively Controlled PI-Networks Using Differentially Controlled Capacitors 68
3.3.1 Concept 69
3.3.2 Differentially Controlled Single-Section PI-Network 71
3.3.3 Differentially Controlled Dual-Section PI-Network 74
3.3.4 Simulations 75
3.3.4.1 Adaptive Impedance Matching 75
3.3.4.2 Insertion Loss 77
3.3.4.3 System Gain 78
3.3.5 Conclusions on Adaptively Controlled PI-Networks 80
3.4 Adaptively Controlled L-Network Using Cascaded Loops 81
3.4.1 Concept 81
3.4.2 Actuation 82
3.4.2.1 Series-LC Network 82
3.4.2.2 Parallel-LC Network 83
3.4.3 Convergence 86
3.4.4 Simulations 88
3.4.4.1 Adaptive Impedance Matching 89
3.4.4.2 System Gain 91
3.4.5 Capacitance Tuning Range Requirement 91
3.4.6 Insertion Loss 94
3.4.7 Tuning Range Requirement 95
3.4.8 Conclusions on Adaptively Controlled L-Network 97
3.5 Adaptive Series-LC Matching Network Using RF-MEMS 98
3.5.1 Adaptive Tuning System 99
3.5.1.1 Series-LC Matching Network 100
3.5.1.2 Capacitance Tuning Range 101
3.5.1.3 Simulations 102
3.5.2 Adaptive RF-MEMS System Design 103
3.5.2.1 RF-MEMS Unit Cell Design 103
3.5.2.2 RF-MEMS Switched Capacitor Array Design 105
3.5.2.3 Pull-in and Pull-Out Voltage Requirements 107
3.5.2.4 High Voltage Driver IC 108
3.5.2.5 Module Insertion Loss 109
3.5.3 Experimental Verification 111
3.5.3.1 RF-MEMS Switched Capacitor Array 111
3.5.3.2 Module Insertion Loss 112
3.5.3.3 Module Distortion 112
3.5.3.4 Adaptive Module Connected to an Antenna 114
3.5.4 Conclusions on Adaptive Series-LC Matching Module 115
3.6 Load Line Adaptation 115
3.6.1 Introduction 115
3.6.2 Concept 116
3.6.3 Implementation of Load Line Adaptation 118
3.6.4 Simulation Results 119
3.6.5 Conclusions on Load Line Adaptation 121
3.7 Conclusions on Adaptive Impedance Control 122
Chapter 4: Adaptive Power Control 123
4.1 Introduction 123
4.1.1 Over-Voltage Protection for Improved Ruggedness 124
4.1.2 Over-Temperature Protection for Improved Ruggedness 124
4.1.3 Under-Voltage Protection for Improved Linearity 125
4.2 Safe Operating Conditions 125
4.3 Power Adaptation for Ruggedness 128
4.3.1 Concept 128
4.3.2 Simulations 130
4.3.3 Over-Voltage Protection Circuit 131
4.3.4 Over-Temperature Protection Circuit 132
4.3.5 Technology 133
4.3.6 Experimental Verification 133
4.3.6.1 Over-Voltage Protection 135
4.3.6.2 Over-Temperature Protection 135
4.4 Power Adaptation for Linearity 137
4.4.1 Concept 137
4.4.2 Simulations 138
4.4.3 Circuit Design 139
4.4.4 Experimental Verification 141
4.5 Conclusions on Adaptive Power Control 143
Chapter 5: Conclusions 145
Appendix A 147
Appendix A: Overview of Adaptively Controlled Matching Networks 147
Appendix B: A Dual-Banding Technique 153
Introduction 153
Dual-Band Equivalent Inductance 153
Appendix C: Transistor Breakdown Voltages 155
Introduction 155
Shorted Source 155
Open Source 156
Resistor as Source 157
Diode as Source Impedance 159
Biasing Circuit Using Feedback 160
Simulations 161
Summary 161
Summary 163
References 164

Produkt-Details

• Erscheint lt. Verlag: 28.10.2010
• Reihe/Serie: Analog Circuits and Signal Processing
• Reihe/Serie: Analog Circuits and Signal Processing
• Zusatzinfo: XV, 153 p.
• Verlagsort: Dordrecht
• Sprache: englisch
• Themenwelt: Mathematik / Informatik ► Informatik ► Netzwerke
• Themenwelt: Informatik ► Weitere Themen ► Hardware
• Themenwelt: Naturwissenschaften ► Chemie ► Analytische Chemie
• Themenwelt: Naturwissenschaften ► Physik / Astronomie ► Festkörperphysik
• Themenwelt: Technik ► Elektrotechnik / Energietechnik
• Themenwelt: Technik ► Nachrichtentechnik
• Schlagworte: Adaptive RF front-ends • Antenna hand-effects • Impedance control • Mobil • Mobile communication • Power amplifier ruggedness
• ISBN-10: 90-481-9935-2 / 9048199352
• ISBN-13: 978-90-481-9935-8 / 9789048199358