Prelims-H8039.qxd 8/24/06 9:48 AM Page i Practical Radio-Frequency Handbook Prelims-H8039.qxd 8/24/06 9:48 AM Page ii Prelims-H8039.qxd 8/24/06 9:48 AM Page iii Practical Radio-Frequency Handbook Fourth edition IAN HICKMAN BSc (Hons), CEng, MIET, MIEEE www.ianhickman.org.uk AMSTERDAM (cid:127) BOSTON (cid:127) HEIDELBERG (cid:127) LONDON (cid:127) NEW YORK (cid:127) OXFORD PARIS (cid:127) SAN DIEGO (cid:127) SAN FRANCISCO (cid:127) SINGAPORE (cid:127) SYDNEY (cid:127) TOKYO Newnes is an imprint of Elsevier Prelims-H8039.qxd 8/24/06 9:48 AM Page iv Newnes is an imprint of Elsevier Linacre House, Jordan Hill, Oxford OX2 8DP 30 Corporate Drive, Burlington, MA 01803 First published 1993 as Newnes Practical RF Handbook Second edition 1997 Reprinted 1999(twice), 2000 Third edition 2002 Reprinted 2004, 2005 Fourth edition 2007 Copyright ©1993, 1997, 2002, 2007, Ian Hickman. Published by Elsevier Ltd. All rights reserved The right of Ian Hickman to be identified as the author of this work has been asserted in accordance with the Copyright, Designs and Patents Act 1988 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:1)44) (0) 1865 843830; fax ((cid:1)44) (0) 1865 853333; email: [email protected]. 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British Library Cataloguing in Publication Data A catalogue record for this book is available from the British Library Library of Congress Cataloguing in Publication Data A catalogue record for this book is available from the Library of Congress ISBN–13: 978-0-7506-8039-4 ISBN–10: 0-7506-8039-3 For information on all Newnes publications visit our web site at www.newnespress.com Typeset by Charon Tec Ltd (A Macmillan Company), Chennai, India www.charontec.com Printed and bound in Great Britain 07 08 09 10 10 9 8 7 6 5 4 3 2 1 Prelims-H8039.qxd 8/24/06 9:48 AM Page v Contents Preface vii Acknowledgements xi 1 Passive components 1 Resistance and resistors 1 Capacitors 4 Inductors and transformers 6 2 Passive circuits 11 3 RF transmission lines 19 Transmission line operation at d.c. 19 Transmission line operation at r.f. 24 4 RF transformers 32 Introduction 32 Transformer basics 32 R.F. considerations 34 Baluns 40 Line transformers 46 5 Couplers, hybrids and directional couplers 49 6 Active components for RF uses 58 7 RF small-signal circuitry 76 8 Modulation and demodulation 87 9 Oscillators 105 10 RF power amplifiers 130 Safety hazards to be considered 130 First design decisions 131 Levellers, VSWR protection, RF routing switches 131 Starting the design 132 Low-pass filter design 132 Discrete PA stages 134 Prelims-H8039.qxd 8/24/06 9:48 AM Page vi vi Contents 11 Transmitters and receivers 156 12 Advanced architectures 171 13 Propagation 181 14 Antennas 192 15 Attenuators and equalizers 209 16 Measurements 214 Measurements on CW signals 214 Modulation measurements 215 Spectrum and network analysers 215 Other instruments 217 Appendix 1 Useful relationships 223 Appendix 2 S-Parameters 229 Appendix 3 Attenuators (pads) 232 Appendix 4 Universal resonance curve 234 Appendix 5 RF cables 235 Appendix 6 Wire gauges and related information 239 Appendix 7 Manufacturers of soft-ferrite and iron-powder cores 242 Appendix 8 Types of modulation – classification 243 Appendix 9 Quartz crystals 245 Appendix 10 Elliptic filters 247 Appendix 11 Screening 258 Appendix 12 Worldwide minimum external noise levels 267 Appendix 13 Frequency allocations and designations 270 Appendix 14 SRDs (Short Range Devices) 274 Index 277 Prelims-H8039.qxd 8/24/06 9:48 AM Page vii Preface The Practical Radio-Frequency Handbook aims to live up to its title, as a useful vade- mecum and companion for all who wish to extend their familiarity with RF technology. It is hoped that it will prove of use to practising electronic engineers who wish to move into the RF design area, or who have recently done so, and to engineers, technicians, amateur radio enthusiasts, electronics hobbyists and all with an interest in electronics applied to radio frequency communications. From this, you will see that it is not intended to be a text- book in any shape or form. Nothing would have been easier than to fill it up with lengthy derivations of formulae, but readers requiring to find these should look elsewhere. Where required, formulae will be found simply stated: they are there to be used, not derived. I have naturally concentrated on current technology but have tried to add a little interest and colour by referring to earlier developments by way of background information, where this was thought appropriate, despite the pressure on space. This pressure has meant that, given the very wide scope of the book (it covers devices, circuits, equipment, systems, radio propagation and external noise), some topics have had to be covered rather more briefly than I had originally planned. However, to assist the reader requiring more infor- mation on any given topic, useful references for further reading are included at the end of most chapters. The inclusion of descriptions of earlier developments is by no means a waste of precious space for, in addition to adding interest, these earlier techniques have a way of reappearing from time to time – especially in the current climate of deregulation. A good example of this is the super-regenerative receiver, which appeared long before the Second World War, did sterling service during that conflict, but was subsequently buried as a has-been: it is now reappearing in highly price-sensitive short-range applications such as remote garage door openers and central locking controllers. Good RF engineers are currently at a premium, and I suspect that they always will be. The reason is partly at least to be found in the scant coverage which the topic receives in university and college courses. It is simply so much easier to teach digital topics, which furthermore – due to the rapid advances being made in the technology – have long seemed the glamorous end of the business. However, the real world is analogue, and com- municating information, either in analogue or digital form, at a distance and without wires, requires the use of electromagnetic radiation. This may be RF, microwave, milli- metre wave or optical and there is a whole technology associated with each. This book deals just with the RF portion of the spectrum, which in earlier editions was taken to mean the range up to 1000MHz. Frequencies beyond this were traditionally taken as the pre- serve of microwave engineers (sometimes, rather unfairly, called ‘plumbers’), involving waveguides, cavity resonators and the like. But with the enormous strides in technology in recent years, particularly in miniaturized surface mount components and high fre- quency transistors, the domain of conventional printed circuit techniques, used at VHF and UHF, has been extended to the areas of 1.5GHz (SOLAS, safety of life at sea, GPS and Glonas, global positioning systems), 2GHz (PCS and DCS for mobile phones) and Prelims-H8039.qxd 8/24/06 9:48 AM Page viii viii Preface beyond (Bluetooth and other technologies in the 2.54GHz ISM band for short range wire- less data links). In this context, an interesting and important development is the shift of large areas of RF design, away from the circuit design team at, e.g. a mobile phone man- ufacturer’s laboratory, to the development facilities of integrated circuit manufacturers. Thus ASICs – application specific integrated circuits – are no longer confined to the digi- tal field. Firms such as Analog Devices, Maxim, Philips and others are steadily introduc- ing a stream of new products integrating more and more of the receive/transmit front end for mobile phones and the corresponding base stations. Dual band ICs, for both 900MHz and 1800MHz bands (GSM and DCS), have appeared, and now also 3G devices – for the third generation of mobile phones. The necessary matching passive components are also widely available, such as SAW and BAW (surface acoustic- and bulk acoustic-wave) filters from manufacturers such as EPCOS (formerly Siemens/Matsushita Components), Fujitsu, Murata and others. Due to recent developments, the whole frequency range, from a few kHz up to around 6GHz is used for an enormous variety of services, including sound broadcasting and tele- vision, commercial, professional, government and military communications of all kinds, telemetry and telecontrol, radio telex and facsimile and amateur radio. There are specialized applications, such as short-range communications and control (e.g. radio microphones, garage door openers) whilst increasingly, RF techniques are involved in non-wireless appli- cations. Examples are wide band cable modems, and the transmission of data with clock frequencies into the GHz range, over fibre optic cables using the FDDI (Fibre-optic digital data interchange) standard. There are also a number of more sinister applications such as ESM, ECM and ECCM (electronic surveillance measures, e.g. eavesdropping; electronic counter measures, e.g. exploitation and jamming; and electronic counter measures, e.g. jamming resistant radios using frequency hopping or direct sequence spread spectrum). Indeed, the pressure on spectrum space has never been greater than it is now and it is people with a knowledge of RF who have to design, produce, maintain and use equipment capable of working in this crowded environment. It is hoped that this book will prove use- ful to those engaged in these tasks. It should be noted that whilst some of the circuits shown indicate component values, this work is not intended as a ‘cookbook’ of ready-made hand-me-down RF circuits, but rather as an introduction to the general principles and techniques of the design and oper- ation of RF circuitry and equipment. This fourth edition has a number of minor additions, deletions and corrections throughout, and substantial new material has been added to Chapters 3 and 12. But the main change concerns the addition of a new Chapter 11. This deals with the advanced architectures, including IF (intermediate frequency) signal processing techniques in superheterodyne receivers, and other related topics. Also important is the upgrading of Appendix 13, which gives details of frequency allo- cations. Annexe 1 covers the documents defining UK frequency allocations. Complete copies and further information may be obtained from the address given in the appendix. Annexe 2 likewise gives brief details of frequency allocations in the USA. Appendix 14 gives information relating to low power, short range radio devices. These represent an explosive area of growth in recent years, for a number of reasons. First, many of these devices require no licence – a great convenience to the end user – although naturally the manufacturer must ensure that such a device meets the applicable specification. Second, due to the very limited range, frequencies can be re-used almost without limit, in a way Prelims-H8039.qxd 8/24/06 9:48 AM Page ix Preface ix not possible in, for example, broadcast applications, or even in PMR (private mobile radio). Details of the relevant specifications are found in Appendix 14. It is hoped that the additions and alterations incorporated in this fourth edition will make the work even more useful to all with an interest in RF technology. Those working in the field professionally include IC designers, circuit and module engineers, equipment engineers and system engineers. IC design is a very specialized area and is consequently not covered in this book. Whilst it is hoped that readers will gain a useful appreciation of RF systems engineering, the main emphasis of the book will be of greatest use to those with an interest in circuit, module and equipment engineering. Ian Hickman