Low-Power CMOS Design for Wireless Transceivers

117 Pages·2003·4.219 MB·English

by  Alireza Zolfaghari (auth.)

Low-Power CMOS Design for
Wireless Transceivers
LOW-POWER CMOS DESIGN
FOR WIRELESS TRANSCEIVERS
ALIREZA ZOLFAGHARI
Resonext Communications, Inc.
Springer Science+Business Media, LLC
Library of Congress Cataloging-in-Publication Data
Alireza Zolfaghari
Low-Power CMOS for Wireless Transceivers
ISBN 978-1-4419-5319-3 ISBN 978-1-4757-3787-5 (eBook)
DOI 10.1007/978-1-4757-3787-5
Copyright © 2003 by Springer Science+Business Media New York
Originally published by Kluwer Academic Publishers in 2003
Softcover reprint of the hardcover 1s t edition 2003
Ali rights reserved. No part ofthis work may be reproduced, stored in a retrieval
system, or transmitted in any form or by any means, electronic, mechanical,
photocopying, microfilming, recording, or otherwise, without the written permission
from the Publisher, with the exception of any material supplied specifically for the
purpose ofbeing entered and executed on a computer system, for exclusive use by
the purchaser of the work.
Printed an acid-free paper.
Contents
1. INTRODUCTION 1
1.1 Wireless Networks 1
1.2 GPS 2
1.3 Overview of Topics 3
2. TRANSCEIVER ARCHITECTURE 5
2.1 Introduction 5
2.2 Receiver Architectures 5
2.2.1 Heterodyne Receivers 5
2.2.2 Homodyne Receivers 7
2.2.3 Image-Reject Receivers 9
2.3 Transmitter Architectures 9
2.3.1 Direct-Conversion Transmitters 10
2.3.2 Two-Step Transmitters 10
2.4 Proposed Transceiver Architecture 11
2.5 Compatibility with GPS 14
3. STACKED INDUCTORS AND
TRANSFORMERS 17
3.1 Introduction 17
3.2 Definitions of the Quality Factor 18
3.3 Large inductors with high self-resonance frequencies 19
3.4 Derivation of Self-Resonance Frequency 21
3.5 Modification of Stacked Inductors 26
3.6 Stacked Transformers 28
3.7 Experimental Results 32
v1 LOW-POWER CMOS DESIGN FOR WIRELESS TRANSCEIVERS
4. RECEIVER FRONT END 41
4.1 Introduction 41
4.2 Low-Noise Amplifier 41
4.3 RF Mixers 45
4.4 First Downconversion 46
4.5 Second Downconversion 52
4.5.1 Divide-by-Two Circuit 52
4.5.2 Passive Mixers 53
5. TRANSMITTER 57
5.1 Introduction 57
5.2 First Upconversion 58
5.3 Second Upconversion 58
5.4 Power Amplifier 61
6. CHANNEL-SELECT FILTER 67
6.1 Introduction 67
6.2 Noninvasive Filtering 67
6.2.1 General Idea 67
6.2.2 Noise Performance 70
6.2.3 Filter Tuning 72
6.3 Filter Design 74
6.3.1 Bluetooth Signal 74
6.3.2 Single-Tone Interferers 74
6.3.3 Intermodulation Specification 76
6.3.4 Order of Filter 76
6.4 Filter Realization 78
6.4.1 Transconductor Stage 78
6.4.2 Input Transconductor and Parallel Resistor 79
6.4.3 Capacitors 80
6.4.4 Channel-Select Filter 82
7. EXPERIMENTAL RESULTS 87
7.1 Introduction 87
7.2 Test Setup 87
7.2.1 Equipment 87
7.2.2 Test Board 88
7.2.3 Noise Figure Measurements at Low Frequencies 88
7.3 First Prototype: RF Front-End Chip 90
7.4 Second Prototype: Transmitter /Receiver Chip 93
8. CONCLUSION 97
REFERENCES 101
Contents vii
Index
105
List of Figures
1.1 GPS signals. 3
2.1 Simple heterodyne receiver. 6
2.2 Image problem. 6
2.3 Homodyne receiver. 7
2.4 Direct-conversion transmitter. 10
2.5 Two-step transmitter. 11
2.6 Transceiver architecture. 12
2.7 Measured characteristic of two antennas operating
back to back. 13
2.8 Power spectral density of GPS signals. 15
2.9 Low-IF GPS receiver. 15
3.1 (a) Low-noise amplifier and {b) mixer with high IF. 19
3.2 Representative VCO. 20
3.3 A two-layer inductor. 20
3.4 (a) Decomposing a spiral into equal sections. {b)
Distributed model of a two-layer inductor. 22
3.5 Voltage profile across each capacitor. 23
3.6 Simulated voltage profile of a single spiral. 25
3.7 Modification of two-layer stacked inductors. 26
3.8 Three-layer stacked inductor modification. 27
3.9 Example of using a transformer to boost current
in an active mixer. 28
3.10 Transformer structure. 29
3.11 Transformer model. 30
3.12 Simulated voltage gain of the transformers. 31
3.13 1-to-4 transformer structure. 31
3.14 Die photo. 32
3.15 Measured inductor characteristics. 33
X LOW-POWER CMOS DESIGN FOR WIRELESS TRANSCEIVERS
3.16 Comparison of one-layer and two-layer structures
for a given value of inductance. 34
3.17 Measured inductors in 0.4-J.tm technology. 35
3.18 Effect of inductor modification on Q. 36
3.19 Effect of inductor modification on selectivity. 37
3.20 Simulation and measurement comparison. 38
3.21 Measured 1-to-2 transformer voltage gain for CL =0,
50 fF, 100 fF, 500 fF, 1 pF. 39
3.22 Measured 1-to-4 transformer voltage gain for CL =0,
50 fF, 100 fF, 500 fF, 1 pF. 40
4.1 Cascode LNA. 42
4.2 Matching circuit to boost the impedance seen at
the gate of the transistor looking into the source. 44
4.3 Single-balanced active mixer. 46
4.4 Conventional circuit for the first downconversion. 47
4.5 (a) Stacking in the first downconversion (b) circuit
implementation. 48
4.6 Improving image rejection in the first downconversion. 49
4.7 First downconversion circuit. 50
4.8 Inductors used in downconversion. 51
4.9 Poly resistance in a MOS capacitor. 52
4.10 Divide-by-2 circuit. 53
4.11 Waveforms in the divide-by-2 circuit. 53
4.12 D-latch circuit. 54
4.13 Differential I and Q outputs of the divider when
loaded by passive mixers. 54
4.14 Second downconversion circuit. 55
5.1 Transmitter block diagram. 57
5.2 First upconversion. 58
5.3 Second upconversion. 59
5.4 Current mirror to convert differential to single-
ended signal. 59
5.5 Negative resistance to boost the gain. 60
5.6 Second upconversion with single-ended output. 60
5.7 Common-mode effect in a single-ended output mixer. 61
5.8 Two-stage power amplifier. 62
5.9 Stacking the driver on top of the output stage. 63
5.10 Matching network to boost the output current. 63
5.11 Power amplifier circuit. 64
5.12 Two-tone test to measure intermodulation distortion. 65
5.13 Simulated transmitter output spectrum. 66
6.1 (a) Conventional filtering (b) noninvasive filtering. 68
List of Figures xi
6.2 Second order noninvasive filter topology. 69
6.3 Transconductor noise model. 70
6.4 Filter noise model. 71
6.5 Filter output noise. 72
6.6 VCO tunning loop. 73
6. 7 Gaussian frequency shift keying ( GFSK) modulation. 74
6.8 Simulated spectrum of a Bluetooth signal. 75
6.9 Interferers in Bluetooth. 75
6.10 Signal and two-tone interferers for n = 3. 76
6.11 GFSK demodulator. 77
6.12 Transconductor circuit. 78
6.13 Transconductor tuning range. 80
6.14 Input transconductor and parallel resistor. 81
6.15 Capacitors in filter: (a) grounded {b) floating. 81
6.16 Differential implementation of the filter. 82
6.17 Baseband amplifier followed by RC filter. 83
6.18 Receiver chain. 84
6.19 Simulated characteristic of the biquad sections. 85
6.20 Simulated output noise of the biquad sections. 86
7.1 Board layouts (a) receiver front end {b) receiver
and filters (c) transmitter. 88
7.2 Output noise power as a function of source temperature. 89
7.3 Receiver front end die photograph. 91
7.4 Measured transmitter spectrum in a narrow span. 92
7.5 Measured transmitter spectrum in a wide span. 93
7.6 Transmitter/receiver die photograph. 94
7. 7 Measured receiver characteristic. 96
List of Tables
1.1 Wireless standards in the 2.4-GHz band. 2
3.1 Measured inductors in 0.25-J.t.m technology {linewidth=
9 p.m, line spacing= 0.72 p.m). 33
3.2 High-value inductors in 0.25-J.t.m technology {linewidth=
9 J.t.m, line spacing= 0. 72 J.t.m, number of turns for
each spiral= 7). 34
4.1 Device dimensions in the first downconversion. 48
6.1 Component values for the filter. 83
7.1 Measured receiver front end performance. 91
7.2 Measured transmitter performance. 92
7.3 Measured receiver performance. 95
7.4 Measured performance of GPS front end. 95