Frequency Synthesis by Phase Lock - Hardcover

Egan, William F.

Hardcover

ISBN 10: 0471321044 ISBN 13: 9780471321040

Publisher: Wiley-Interscience, 1999

Synopsis

A through discussion of frequency synthesizers, including design and effects on systems Working engineers who design, specify, use, or test frequency synthesizers need to develop an intimate understanding of how these devices operate and their effects on the systems in which they are embedded. Frequency Synthesis by Phase Lock, Second Edition, offers complete coverage that includes both normal control system design and effects that occur due to sampling when bandwidths are pushed. While the discussion emphasizes phase-locked synthesizers, direct and digital synthesizers are covered as well. In addition to the usual discussion of second-order loops, this book describes characteristics of an important class of third-order loops and state-space analysis of loops of arbitrary order. It uses Matlab scripts (available for downloading via ftp) to produce computer-aided analyses, including complex nonlinear simulations of loops in the acquisition process; and it includes a significant volume of material on phase noise, its effects in synthesizer loops, and its impact on systems employing synthesizers. An important reference of rare power and clarity, Frequency Synthesis by Phase Lock, Second Edition, features:
* Three new chapters covering architectures, sampling effects, and computer-aided engineering (CAE)
* Multicurve graphs of transient and modulation responses for second-and third-order loops
* Graphs of phase noise from 28 oscillators and 19 frequency dividers; noise theory and curves for IC oscillators
* Charge-pump phase-frequency detectors extensively covered
* Fractional-N, including DSP for improved spectrums
* Multiple loops, including offset references

About this title

About the Author

WILLIAM F. EGAN, PhD, is an instructor at Santa Clara University, Santa Clara, California, and formerly a Principal Engineer at TRW ASD.

Excerpt. © Reprinted by permission. All rights reserved.

FREQUENCY SYNTHESIS BY PHASE LOCK

By WILLIAM F. EGAN

JOHN WILEY & SONS, INC.

Copyright © 2000 John Wiley & Sons, Inc.
All right reserved.
ISBN: 978-0-471-32104-0

Contents

PREFACE.............................................................xviiGETTING FILES FROM THE WILEY INTERNET SITES.........................xxiSYMBOLS LIST AND GLOSSARY...........................................xxiii1 INTRODUCTION......................................................12 THE ELEMENTARY PHASE-LOCKED SYNTHESIZER...........................353 MODULATION, SIDEBANDS, AND NOISE SPECTRUMS........................714 FREQUENCY DIVIDERS................................................1395 PHASE DETECTORS...................................................1756 HIGHER-ORDER LOOPS................................................2457 SAMPLING EFFECTS..................................................3018 ARCHITECTURES.....................................................3439 LARGE-SIGNAL PERFORMANCE, NATURAL ACQUISITION.....................39910 ACQUISITION AIDS.................................................44511 SPECTRAL PURITY..................................................49112 COMPUTER-AIDED ENGINEERING.......................................515REFERENCES..........................................................569ANSWERS TO PROBLEMS.................................................581INDEX...............................................................585Cross-Reference from First Edition..................................597

Preface

The first edition of Frequency Synthesis by Phase Lock was written when radios, televisions, and RF instruments were commonly tuned by knobs, something that has been all but forgotten due to today's widespread use of frequency synthesizers. While synthesizers have become common, they still represent a fascinating and challenging area of electronic design. A synthesizer is a compact, but complex, system, one whose design requires knowledge of RF, analog, digital, and control system technologies, yet is small enough that one engineer can know it in detail. It contains fast digital signals in the volt range and analog signals that must be shielded from those transients to the nanovolt level. The loop itself is a sample data control system with signal-dependent sampling rate, practically unanalyzable but offering opportunity for the clever use of approximation. It is so fascinating and complex that an engineer's first synthesizer design is likely to provide a very significant learning experience.

This book is written for engineers who design, specify, use, or test frequency synthesizers. It is not a "cookbook," not a simplified instruction manual for synthesizer design. The nature of the synthesizer design problem makes such design formulations apply only to limited cases. Moreover, I believe it is important that engineers have a basic understanding of their design. Otherwise, we are at the mercy of misinterpretations of, or factual errors in, reference materials which, I have found, are often of great value but rarely infallible. An engineer should maintain an awareness of what results are reasonable and this requires the kind of understanding that I hope this book will foster. Where there is a schematic in this book, it rarely includes component values; it is intended that the engineer should gain an understanding of that circuit and apply it to his or her particular situation.

Frequency Synthesis is for engineers who want to gain an understanding of synthesizers and their effects on the systems in which they are embedded. It is for engineers who have designed a synthesizer (perhaps using a cookbook) and now want to understand the design. It is for engineers who wish to take the time to study before designing a synthesizer in order to avoid problems.

Within the subject area of synthesizers, the phase-locked type is strongly emphasized, but the other types, direct and digital, are not ignored. Their operating principles are described and fundamentals applicable to their design and use are discussed, but phase-lock techniques, which are probably the most commonly used, are emphasized.

Some of the material is from the first edition-those fundamentals still apply-but much of the material is new, reflecting subsequent developments. The first edition was designed largely as a text for use in graduate courses. I have used it for this purpose, but such courses are not common. Problems, most from the first edition, are included, and answers have now been provided for most of these, making the problems more useful for self-study. Numerous examples are included, as before.

Because of the complexity of the synthesizer loop, simulation is important. In the first edition, I could only describe computer-aided engineering (CAE) programs that were run on large computers. Happily, we now have available commercial CAE programs for PCs, which are discussed in Chapter 12. In addition, I have made available MATLAB(r) scripts for use as design aids and as aids to understanding. These tools for synthesizer analysis and simulation can be downloaded from the Wiley ftp site. (See Figures 12.13 through 12.15 and Figure 9.18 for CAE examples.) Moreover, the descriptions in the text and comments in the scripts are intended to allow the reader to understand the details of these scripts so they can be further extended and expanded, possibly used in other software languages. The ftp site also provides a vehicle for making (the practically inevitable) errata available.

Extensive references have been provided to lead the reader to a better understanding of related material that is not covered in detail, or where a more extensive, or simply alternate, treatment may be available. One significant impediment in using such references is the wide variety of symbols used in the literature. Fortunately, Phase-Lock Basics [Egan, 1998] provides a convenient reference for a more detailed understanding of basic material, with symbols that correspond closely to those used in this book. Because it will be referenced frequently, it will be abbreviated PLB and not accompanied by the standard [Egan, 1998] pointer to the description of a work under the References section in the back of this book. While Frequency Synthesis is self-contained, references to PLB can provide an avenue for gaining understanding at a more basic level or in more general areas of phase lock. In addition, some of the MATLAB scripts used with PLB, which are also available from the Wiley ftp site, are referenced.

There is a potential problem that affects phase-locked loop design and often leads to 2[pi] errors in numerical values, resulting from the variety of units used for phase. The first edition of this book guarded against such errors by using subscripts to indicate whether cycle or radian units were being used for a variable. In the second edition, we follow a procedure that makes this unnecessary, permitting free choice of units while avoiding 2[pi] errors.

Chapter 1 introduces the concepts of frequency synthesis, including the three basic synthesizer forms. Chapter 2 provides, as a starting point, an elementary understanding of the phase-locked synthesizer, including its components and the design problem.

The critical concept of phase noise is discussed in Chapter 3, including its impact on systems using synthesizers, noise levels in synthesizer components, and the effect of the synthesizer in processing these noise levels. The extensive curves of oscillator phase-noise density, given in the first edition, have been further expanded and typical frequency-divider noise curves have been added.

Chapters 4 and 5 provide ample discussion of two critical synthesizer components, frequency dividers and phase detectors, respectively. Crossover distortion ("the dead zone") in charge-pump phase-frequency detectors is covered extensively.

Chapter 6 extends the elementary synthesizer concepts learned in Chapter 2 to higher-order loops, including exact analysis of an important class of third-order loops and a description of state-space methods applicable to even higher orders. The latter are employed extensively in the MATLAB scripts for simulation of the synthesizer as it acquires lock.

Chapter 7 discusses sampling in the synthesizer and its important, but somewhat obscure, effects on loop performance, especially stability. Various methods for analyzing these effects are given.

Chapter 8 describes advanced synthesizer architectures, including the incorporation of heterodyning, multiple loops, and fractional-N synthesis. The use of digital signal processing to reduce spurious content in fractional-N synthesis, which was discussed in the first edition, is here expanded to include more sophisticated variants.

Chapter 9 discusses large-signal performance during frequency switching and acquisition of lock, including many formulas for various kinds of loops and a discussion of the phenomena of false locks and limited oscillations. Chapter 10 describes acquisition aids, including phase-frequency detectors and learning sequences.

Spectral purity, its attainment, measurement, and computations are discussed in Chapter 11.

Chapter 12 describes CAE, focusing on the various aids provided by MATLAB scripts, as well as commercial CAE programs.

I hope that this book will be a valued resource for engineers engaged in all aspects of synthesizer design and use, and that it conveys some of the fascination I have found in this area of engineering.

The manuscript was reviewed by Eric Unruh, a colleague and fellow synthesizer designer, whose suggestions were greatly appreciated and will surely benefit the reader.

William F. Egan Cupertino, California August 1999

(Continues...)

Excerpted from FREQUENCY SYNTHESIS BY PHASE LOCKby WILLIAM F. EGAN Copyright © 2000 by John Wiley & Sons, Inc.. Excerpted by permission.
All rights reserved. No part of this excerpt may be reproduced or reprinted without permission in writing from the publisher.
Excerpts are provided by Dial-A-Book Inc. solely for the personal use of visitors to this web site.

Edition details

• Publisher: Wiley-Interscience
• Publication date: 1999
• Language: English
• ISBN 10: 0471321044
• ISBN 13: 9780471321040
• Binding: Hardcover
• Edition number: 2
• Number of pages: 628