Analog CMOS Filters for Very High Frequencies

238 Pages·1993·7.27 MB·English

by  Bram Nauta (auth.)

ANALOG CMOS FILTERS FOR
VERY HIGH FREQUENCIES
THE KLUWER INTERNATIONAL SERIES
IN ENGINEERING AND COMPUTER SCIENCE
ANALOG CIRCUITS AND SIGNAL PROCESSING
Consulting Editor
Mohammed Ismail
Ohio State University
ANALOG CMOS FILTERS FOR
VERY HIGH FREQUENCIES
by
Bram Nauta
Philips Research Laboratories
~.
"
SPRINGER SCIENCE+BUSINESS MEDIA, LLC
Library ofCongress Cataloging-in-Publication Data
Nauta, Bram, 1964-
Analog CMOS filters for very high frequencies / by Bram Nauta.
p. cm. -- (The K1uwer international series in engineering and
computer science. Analog circuits and signal processing)
Includes bibliographieal references and index.
ISBN 978-1-4613-6591-4 ISBN 978-1-4615-3580-5 (eBook)
DOI 10.1007/978-1-4615-3580-5
1. Electric filters--Design and construction. 2. Metal oxide
semiconductors, Complementary. 3. Integrated circuits. 1. Title.
II. Series.
TK7872.F5N38 1993
621.3815 324--dc20 92-27778
I
CIP
Copyright © 1993 by Springer Science+Business Media New York
Originally published by Kluwer Academic Publishers, New York in 1993
Softcover reprint ofthe hardcover 1st edition 1993
All rights reserved. No part of this publication may be reproduced, stored in a retrieval
system or transmi tted in any form or by any means, mechanical, photo-copying, recording,
or otherwise, without the prior written permission of the publisher, Springer Science+
Business Media, LLC.
Printed on acid-free paper.
To Ellen
CONTENTS
PREFACE xi
1 INTRODUCTION
1 .1 Introduction
1.2 Active monolithic filters, an overview
1.3 Monolithic analog continuous-time filters 4
1. 4 Research topics 10
2 FILTER SYNTHESIS FOR (VERY) HIGH FREQUENCIES 11
2.1 Introduction 11
2.2 Restrictions for very high frequencies 11
2.3 Synthesis methods 14
2.3.1 Cascaded biquad synthesis 15
2.3.1.1 Biquads 15
2.3.1.2 Example 15
2.3.1.3 Conclusions 16
2.3.2 Signal flow graph synthesis 17
2.3.2.1 Introduction 17
2.3.2.2 Example 17
2.3.2.3 Conclusions 22
2.3.3 State-space synthesis 23
2.3.3.1 State-space synthesis 23
2.3.3.2 Example 24
2.3.3.3 Conclusions 27
2.3.4 Gyrator synthesis 28
2.3.4.1 Gyrators 28
2.3.4.2 Gyrator filter synthesis 31
2.3.4.3 Examples 34
2.3.4.4 Conclusions 36
2.3.5 Coupled resonator bandpass filters 36
2.3.5.1 Design technique 36
2.3.5.2 Examples 39
viii Contents
2.3.5.3 Conclusions 40
2.3.6 Comparison of synthesis methods 41
2.4 Sensitivity 42
2.4.1 Sensitivity of LC-Iadder filters 42
2.4.2 Sensitivity of gyrator filters 42
2.4.3 Sensitivity of other filters 46
2.5 Frequency and impedance level scaling 47
2.6 Conclusions 48
3 EFFECT OF NON-IDEALITIES 49
3.1 Introduction 49
3.2 Effect of finite integrator quality factor 49
3.2.1 Integrator model 49
3.2.2 Effect of finite integrator quality factor 53
3.2.3 Gyrators 62
3.2.4 Canceling of effects of overlap capacitances
in a balanced gyrator 65
3.3 Dynamic range 70
3.3.1 Noise 70
3.3.2 Distortion 73
3.3.3 Noise and distortion gives dynamic range 78
3.4 Dissipation and chip area 79
3.5 Capacitors 81
3.6 Conclusions 83
4 TRANSCONDUCTOR DESIGN 85
4.1 The MOS Transistor 85
4.2 Linear MOS transconductors, an overview 87
4.3 Design strategy for VHF transconductor 92
4.4 VHF transconductor, basic operation 94
4.4.1 V-I conversion 95
4.4.2 Common-mode control and DC-gain enhancement 97
4.4.3 Conclusions 101
4.5 Detailed analysis and measurements 102
4.5.1 Output conductance 103
4.5.2 Transconductor bandwidth 105
Contents ix
4.5.3 Series resistances in capacitors 111
4.5.4 Transconductor-C integrator quality factor 112
4.5.5 Noise 117
4.5.6 Distortion 120
4.5.6.1 Nonlinearities in V-I conversion 121
4.5.6.2 Nonlinearities in output conductance 125
4.5.7 Dynamic range 130
4.5.8 Dissipation 132
4.5.9 Parasitic capacitors 132
4.6 Conclusions 135
5 TUNING 137
5.1 Introduction 137
5.2 The VCO tuning loop 139
5.3 Quality factor tuning 141
5.3.1 Basic principle 141
5.3.2 Implementation 144
5.3.3 Experimental results 148
5.4 Supply voltage unit 149
5.4.1. Introduction 149
5.4.2 Basic principle 152
5.4.3 Implementations 154
5.5 Conclusions 161
6 FILTER REALIZATIONS 163
6.1 Introduction 163
6.2 Third-order elliptic filters 163
6.2.1 Filter design 163
6.2.2 Experimental setup 168
6.2.3 Experimental results 170
6.2.4 Conclusions, third-order elliptic filters 182
6.3 TV IF Filter 183
6.3.1 Introduction 183
6.3.2 TV front-end 184
6.3.3 Filter specification 186
x Contents
6.3.4 IF filter design 189
6.3.5. Experimental results 199
6.3.6 Conclusions, TV IF filter. 209
7 CONCLUSIONS 211
7.1 Introduction 211
7.2 Summary 211
7.3 Original contributions to the thesis 214
7.4 Recommendations for further research 216
REFERENCES 219
SUBJECT INDEX 229
PREFACE
This book deals with the design of fully integrated analog CMOS filters for very high
frequencies. It describes various synthesis methods and electronic circuit designs
suitable for filters with cut-off frequencies ranging from the low megahertz range to
several hundreds of megahertz. The book is intended for engineers in research or
development and advanced level students.
Today IC technology is widely used for fully integration of electronic systems. These
systems are in general for a large part realized using digital techniques implemented
in CMOS technology. The low power dissipation, high packing density, high noise
immunity, ease of design and the relative ease of scaling are the driving forces of
CMOS technology for digital applications. Parts of these systems cannot be implemented
in the digital domain and will remain analog. In order to achieve complete system
integration these analog functions are preferably integrated in the same CMOS
technology. An important class of analog circuits that need to be integrated in CMOS
are analog filters.
This book deals with very high frequency (VHF) filters, which are filters with cut-off
frequencies ranging from the low megahertz range to several hundreds of megahertz. Up
till recently the maximal cut-off frequencies of CMOS filters were limited to the low
megahertz range. By applying the techniques presented in this book the limit could be
pushed into the true VHF domain, and integrated VHF filters became feasible.
Application of these VHF filters can be found in the field of communication,
instrumentation and control systems. For example pre and post filtering for high-speed
AD and DA converters, signal reconstruction, signal decoding, etc.
The general design philosophy used in this book is, to allow only the absolute minimum
of signal carrying nodes throughout the whole filter. This strategy starts at the
filter synthesis level and is extended to the level of electronic circuitry. The
result is a filter realization in which all capacitors (including parasitics) have a
desired function. The advantage of this technique is that high-frequency parasitic
effects (parasitic poles/zeros) are minimally present.
The first part of the book (chapters 1-3) is on general design for VHF filters,
including synthesis methods and analysis of the effects of various non-idealities. The
second part (chapters 4-6) describes more specific electronic circuitry suitable for
implementing these VHF filters in CMOS technology. This part also includes the
experimental results of several demonstration filters. An outline of each chapter is