RF Front-End World Class Designs Newnes World Class Designs Series Analog Circuits: World Class Designs Robert A. Pease ISBN: 978-0-7506-8627-3 Embedded Systems: World Class Designs Jack Ganssle ISBN: 978-0-7506-8625-9 Power Sources and Supplies: World Class Designs Marty Brown ISBN: 978-0-7506-8626-6 FPGAs: World Class Designs Clive “Max” Maxfi eld ISBN: 978-1-85617-621-7 Digital Signal Processing: World Class Designs Kenton Williston ISBN: 978-1-85617-623-1 Portable Electronics: World Class Designs John Donovan ISBN: 978-1-85617-624-8 RF Front-End: World Class Designs Janine Sullivan Love ISBN: 978-1-85617-622-4 For more information on these and other Newnes titles visit: www.newnespress.com RF Front-End World Class Designs Janine Sullivan Love with Cheryl Ajluni John Blyler Christopher Bowick Joe Carr Farid Dowla Michael Finneran Andrei Grebennikov Ian Hickman Leo G. Maloratsky Ian Poole Nathan O. Sokal Steve Winder Hank Zumbahlen AMSTERDAM • BOSTON • HEIDELBERG • LONDON NEW YORK • OXFORD • PARIS • SAN DIEGO SAN FRANCISCO • SINGAPORE • SYDNEY • TOKYO Newnes is an imprint of Elsevier Newnes is an imprint of Elsevier 30 Corporate Drive, Suite 400, Burlington, MA 01803, USA Linacre House, Jordan Hill, Oxford OX2 8DP, UK Copyright © 2009, Elsevier Inc. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of the publisher. Permissions may be sought directly from Elsevier’s Science & Technology Rights Department in Oxford, UK: phone: ((cid:2) 44) 1865 843830, fax: ( (cid:2) 44) 1865 853333, E-mail: [email protected] . 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ISBN: 978-1-85617-622-4 For information on all Newnes publications visit our Web site at w ww.elsevierdirect.com 09 10 11 10 9 8 7 6 5 4 3 2 1 Printed in the United States of America Contents Preface ..............................................................................................................xi About the Editor ............................................................................................... xiii About the Contributors .......................................................................................xv Chapter 1: Radio Waves and Propagation ..............................................................1 1.1 Electric Fields .................................................................................................................1 1.2 Magnetic Fields ...............................................................................................................3 1.3 Radio Waves ....................................................................................................................3 1.4 Frequency to Wavelength Conversion .............................................................................5 1.5 Radio Spectrum ...............................................................................................................6 1.6 Polarization .....................................................................................................................7 1.7 How Radio Signals Travel ..............................................................................................9 1.8 Refraction, Refl ection and Diffraction ..........................................................................10 1.9 Refl ected Signals ...........................................................................................................12 1.10 Layers above the Earth ..................................................................................................13 1.11 Ground Wave .................................................................................................................17 1.12 Skywaves .......................................................................................................................18 1.13 Distances and the Angle of Radiation ...........................................................................21 1.14 Multiple Refl ections ......................................................................................................22 1.15 Critical Frequency .........................................................................................................23 1.16 MUF ..............................................................................................................................23 1.17 LUF ...............................................................................................................................24 1.18 Skip Zone ......................................................................................................................24 1.19 State of the Ionosphere ..................................................................................................24 1.20 Fading ............................................................................................................................25 1.21 Ionospheric Disturbances ..............................................................................................26 1.22 Very Low Frequency Propagation .................................................................................27 1.23 VHF and Above ............................................................................................................28 1.24 Greater Distances ..........................................................................................................28 wwwwww..nneewwnneesspprreessss..ccoomm vi Contents 1.25 Troposcatter ...................................................................................................................29 1.26 Sporadic E .....................................................................................................................30 1.27 Meteor Scatter ...............................................................................................................31 1.28 Frequencies above 3 GHz .............................................................................................32 Chapter 2: RF Front-End Design .........................................................................33 2.1 Higher Levels of Integration .........................................................................................34 2.2 Basic Receiver Architectures ........................................................................................36 2.3 ADC’S Effect on Front-end Design ..............................................................................57 2.4 Software Defi ned Radios ..............................................................................................58 2.5 Case Study—Modern Communication Receiver ..........................................................59 Chapter 3: Radio Transmission Fundamentals for WLANs .....................................65 3.1 Defi ning Transmission Capacity and Throughput ........................................................65 3.2 Bandwidth, Radios, and Shannon’s Law ......................................................................67 3.3 Bandwidth Effi ciency ....................................................................................................69 3.4 Forward Error Correction (FEC) ...................................................................................71 3.5 Radio Regulation ...........................................................................................................72 3.6 Licensed Versus Unlicensed Radio Spectrum ...............................................................73 3.7 Unlicensed Spectrum in the Rest of the World .............................................................75 3.8 General Diffi culties in Wireless ....................................................................................76 3.9 Basic Characteristics of 802.11 Wireless LANs ...........................................................81 3.10 Conclusion ....................................................................................................................82 Chapter 4: Advanced Architectures ......................................................................83 References ................................................................................................................................94 Chapter 5: RF Power Amplifi ers ..........................................................................95 5.1 Power Amplifi er Class of Operation .............................................................................96 5.2 Conclusion ..................................................................................................................113 References ..............................................................................................................................114 Chapter 6: RF Amplifi ers .................................................................................115 6.1 Noise and Preselectors/Preamplifi ers ..........................................................................116 6.2 Amplifi er Confi gurations ............................................................................................117 6.3 Transistor Gain ............................................................................................................117 6.4 Classifi cation by Common Element ............................................................................118 6.5 Transistor Biasing .......................................................................................................120 wwwwww..nneewwnneesspprreessss..ccoomm Contents vii 6.6 Frequency Characteristics ...........................................................................................122 6.7 JFET and MOSFET Connections ...............................................................................123 6.8 JFET Preselector .........................................................................................................123 6.9 VHF Receiver Preselector ...........................................................................................127 6.10 MOSFET Preselector ..................................................................................................127 6.11 Voltage-tuned Receiver Preselector ............................................................................129 6.12 Broadband RF Preamplifi er for VLF, LF and AM BCB .............................................129 6.13 Push-pull RF Amplifi ers .............................................................................................132 6.14 Broadband RF Amplifi er (50 Ohm Input and Output) ................................................138 Chapter 7: Basics of PA Design .........................................................................141 7.1 Spectral-domain Analysis ...........................................................................................141 7.2 Basic Classes of Operation: A, AB, B, and C .............................................................147 7.3 Active Device Models .................................................................................................156 7.4 High-Frequency Conduction Angle ............................................................................162 7.5 Nonlinear Effect of Collector Capacitance .................................................................169 7.6 Push–Pull Power Amplifi ers .......................................................................................172 7.7 Power Gain and Stability ............................................................................................178 7.8 Parametric Oscillations ...............................................................................................189 References ..............................................................................................................................193 Chapter 8: Power Amplifi ers .............................................................................197 8.1 Safety Hazards to Be Considered................................................................................197 8.2 First Design Decisions ................................................................................................198 8.3 Levelers, VSWRP, RF Routing Switches ...................................................................199 8.4 Starting the Design ......................................................................................................199 8.5 Low-pass Filter Design ...............................................................................................200 8.6 Discrete PA Stages ......................................................................................................203 References ..............................................................................................................................226 Chapter 9: RF/IF Circuits .................................................................................227 9.1 Mixers .........................................................................................................................229 9.2 Modulators ..................................................................................................................235 9.3 Analog Multipliers ......................................................................................................236 9.4 Logarithmic Amplifi ers ...............................................................................................243 9.5 Tru-Power Detectors ...................................................................................................248 9.6 VGAs ..........................................................................................................................251 9.7 Direct Digital Synthesis ..............................................................................................259 wwwwww..nneewwnneesspprreessss..ccoomm viii Contents 9.8 PLLs ............................................................................................................................268 Bibliography ..........................................................................................................................289 Chapter 10: Filters ..........................................................................................293 10.1 Classifi cation ...............................................................................................................293 10.2 Filter Synthesis ............................................................................................................296 10.3 LPFs ............................................................................................................................297 10.4 BPFs ............................................................................................................................305 References ..............................................................................................................................321 Chapter 11: Transmission Lines and PCBs as Filters ............................................325 11.1 Transmission Lines as Filters ......................................................................................326 11.2 Open-circuit Line ........................................................................................................327 11.3 Short-circuit Line ........................................................................................................328 11.4 Use of Misterminated Lines ........................................................................................329 11.5 Printed Circuits as Filters ............................................................................................336 11.6 Bandpass Filters ..........................................................................................................338 References ..............................................................................................................................339 Chapter 12: Tuning and Matching .....................................................................341 12.1 Vectors for RF Circuits ...............................................................................................341 12.2 L-C Resonant Tank Circuits ........................................................................................344 12.3 Tuned RF/IF Transformers ..........................................................................................348 12.4 Construction of RF/IF Transformers ...........................................................................349 12.5 Bandwidth of RF/IF Transformers ..............................................................................351 12.6 Choosing Component Values for L–C Resonant Tank Circuits ..................................355 12.7 The Tracking Problem .................................................................................................357 12.8 The RF Amplifi er/Antenna Tuner Problem ................................................................358 12.9 The Local Oscillator (LO) Problem ............................................................................361 12.10 Trimmer Capacitor Method .........................................................................................361 12.11 Impedance Matching in RF Circuits ...........................................................................363 12.12 Transformer Matching ................................................................................................363 12.13 Resonant Transformers ...............................................................................................364 12.14 Resonant Networks .....................................................................................................366 12.15 Inverse-L Network ......................................................................................................367 12.16 π-network ...................................................................................................................367 12.17 Split-capacitor Network ..............................................................................................368 12.18 Transistor-to-Transistor Impedance Matching ............................................................369 wwwwww..nneewwnneesspprreessss..ccoomm Contents ix Chapter 13: Impedance Matching ......................................................................373 13.1 Background .................................................................................................................373 13.2 The L Network ............................................................................................................376 13.3 Dealing with Complex Loads .....................................................................................380 13.4 Three-element Matching .............................................................................................383 13.5 Low-Q or Wideband Matching Networks ...................................................................389 13.6 The Smith Chart ..........................................................................................................395 13.7 Impedance Matching on the Smith Chart ...................................................................414 13.8 Software Design Tools ................................................................................................422 13.9 Summary .....................................................................................................................439 Chapter 14: RF Power Amplifi er Linearization Techniques ...................................441 14.1 RF Amplifi er Nonlinearity ..........................................................................................442 14.2 Linearization Techniques ............................................................................................445 14.3 Digital Baseband Predistortion ...................................................................................450 14.4 Conclusion ..................................................................................................................458 References ..............................................................................................................................458 Index ..............................................................................................................461 wwwwww..nneewwnneesspprreessss..ccoomm