Radio design in nanometer technologies

RADIO DESIGN IN NANOMETER TECHNOLOGIES

Radio Design in Nanometer Technologies Edited by

MOHAMMED ISMAIL The Ohio State University, Columbus, OH, U.S.A. and

DELIA RODRÍGUEZ DE LLERA GONZÁLEZ The Royal Institute of Technology, Stockholm, Sweden

A C.I.P. Catalogue record for this book is available from the Library of Congress.

ISBN-10 ISBN-13 ISBN-10 ISBN-13

1-4020-4823-8 (HB) 978-1-4020-4823-4 (HB) 1-4020-4824-6 (e-book) 978-1-4020-4824-1 (e-book)

Published by Springer, P.O. Box 17, 3300 AA Dordrecht, The Netherlands. www.springer.com

Printed on acid-free paper

All Rights Reserved © 2006 Springer No part of this 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 written permission from the Publisher, with the exception of any material supplied specifically for the purpose of being entered and executed on a computer system, for exclusive use by the purchaser of the work.

Ismail would like to dedicate this work to his family. Para todos los que han hecho ı una persona mejor. de m´ Con todo mi carino. ˜ Delia

Contents

List of Figures List of Tables Preface Acknowledgment Part I

xi xxi xxiii xxvii

Current and Future Trends

1. “4G" AND THE WIRELESS WORLD 2015 - CHALLENGES IN SYSTEM ARCHITECTURES AND COMMUNICATION PARADIGMS 1 Introduction 2 From the “Swiss Army Knife" .... 3 ... to Navigating the “Wireless Chaos" 4 Six “Grand Challenges" in Wireless Systems 5 Challenges in Radio Design - Flexible or Software Defined Radios 6 Conclusions References

9 9 10

2. CELLULAR RF REQUIREMENTS AND INTEGRATION TRENDS 1 Handset Technology Drivers 2 RF Transceiver Design Challenges 3 Architectures 4 Technology Scaling 5 Handset Implementation Trends References

11 11 16 23 28 31 33

vii

3 3 4 5 7

viii

RADIO DESIGN IN NANOMETER TECHNOLOGIES

3. SOFTWARE DEFINED RADIO — VISIONS, CHALLENGES AND SOLUTIONS 1 Introduction 2 Technical Visions 3 Some Comments on Frequency Planning 4 The Radio Challenge 5 Power Consumption of the Analog to Digital Converter 6 Other Key Components 7 Example of a 160MHz Carrier SDR Front-End 8 Example of a 2.4GHz Carrier Front-End 9 Conclusion References Part II

35 35 36 38 40 44 48 49 50 53 55

Digital SOC Design

4. TRENDS IN SOC ARCHITECTURES 1 Introduction 2 VLSI Design Space 3 Conclusion 4 Acknowledgement References

59 59 62 79 80 80

5. PROGRAMMABLE BASEBAND PROCESSORS 1 Introduction 2 Baseband Processing Challenges 3 Programmable Baseband Processors 4 OFDM and WCDMA Example 5 Multi-Standard Processor Design 6 Conclusion References

83 83 84 86 88 94 99 99

6. ANALOG-TO-DIGITAL CONVERSION TECHNOLOGIES FOR SOFTWARE DEFINED RADIOS 1 Introduction 2 Why Software Defined Radios? 3 Commercial SDRs and SRs 4 Current and Future Radio Architectures

101 101 102 103 104

ix

Contents

5 Analog-To-Digital Conversion Challenges 6 Reconfigurable ADCs for SDR/SR 7 Conclusions References 7. RECONFIGURABLE A/D CONVERTERS FOR FLEXIBLE WIRELESS TRANSCEIVERS IN 4G RADIOS 1 Introduction 2 Towards 4G Radios 3 Flexible Receiver Architectures 4 Multi-standard A/D Converters References Part III

108 112 119 120 123 123 124 126 127 140

Radio Design

8. RECEIVER DESIGN FOR INTEGRATED MULTI-STANDARD WIRELESS RADIOS 1 Introduction 2 Multi-standard Receiver Design Considerations 3 From Standard to Receiver Specs 4 Frequency Planning 5 Receiver Budget 6 Case Study:WCDMA/WLAN Receiver Budget 7 Conclusions References

145 145 148 149 156 160 165 169 170

9. ON-CHIP ESD PROTECTION FOR RFICS 1 Introduction 2 Full-chip Protection Topology 3 ESD Protection Circuits for RF I/Os 4 Inductor-based Protection Circuits 5 ESD Testing of RFICs References

173 173 173 175 181 189 190

10. SILICON-BASED MILLIMETER-WAVE POWER AMPLIFIERS 1 Introduction 2 Challenges in Microwave/Millimeter-Wave Power Amplifier Design

193 193 194

x

RADIO DESIGN IN NANOMETER TECHNOLOGIES

3 4 5

Power Amplifier Design Approaches Power Combining Techniques Case Study: Design of a 24GHz Power Amplifier Based on Distributed Active Transformer 6 Summary and Conclusions References

196 202 205 212 214

11. MONOLITHIC INDUCTOR MODELING AND OPTIMIZATION 1 Monolithic Inductor Modeling 2 The Inductor CAD-Tool Indentro 3 Verification of the Capacitance Model References

217 218 230 233 238

12. CHALLENGES IN THE DESIGN OF PLLS IN DEEP-SUBMICRON TECHNOLOGY 1 Introduction 2 Technology Trends 3 PLL Performance Metrics 4 Impact of Technology Scaling 5 Architecture Landscape References

241 241 241 247 261 272 284

13. RFIC DESIGN FOR FIRST-PASS SILICON SUCCESS 1 Introduction 2 SoC Integration 3 Self Awareness 4 Self Calibration 5 Self Configuration 6 Leveraging Self Configuration for System Parameters 7 Conclusion References

287 287 295 305 308 312 312 314 314

About the Authors

315

Index

321

List of Figures

1.1 1.2

2.1 2.2 2.3 2.4 2.5 2.6

2.7 2.8 2.9 2.10 2.11 2.12 2.13 2.14 2.15 2.16 2.17 2.18

Range/Coverage/Mobility - Bandwidth relationship. Heterogeneous wireless infrastructure with a multitude of access with varying properties (range, data rate, mobility etc.) GH197 (1992). T28 (1999). T39 (2000). Tentative handset block diagram. Image response. Intermodulation products resulting from 0.9 cos(5∆ωt)+ 1.1 cos(7∆ωt) √applied to a cubic nonlinearity with IP2 = 5 and IP3 = 2. Linearity definitions; intercept points, compression point and spurious-free dynamic range. Selectivity and blocking dynamic range requirements. Receiver domain partitioning. Receiver architecture genealogy. Double super heterodyne receiver (less antenna filters). Single conversion zero-IF receiver. Single-conversion low-IF receiver with poly-phase IF filter. Direct up-conversion transmitter. Direct phase-modulation transmitter. Polar modulation transmitter. Single-chip Bluetooth modem. Single-chip Bluetooth transceiver.

xi

4

6 12 13 14 15 16

18 19 20 21 23 24 24 25 26 27 28 29 30

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RADIO DESIGN IN NANOMETER TECHNOLOGIES

2.19 2.20 3.1 3.2 3.3 3.4 3.5 3.6 3.7

3.8

3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 4.1 4.2 4.3 4.4 4.5 4.6

Single-chip GPRS transceiver. Handset internal interfaces. "Ideal" software defined radio. Double superheterodyne receiver. Homodyne transceiver. Frequency planning for a superheterodyne (b) and a homodyne (c). I/Q-sampling utilizing fs =4fc /3. Frequency planning for I/Q sampling with various fc /fs ratios. Performance of various published ADCs plotted as sampling frequency versus resolution. We also show our target performance fs 22n =1.6·1016 Hz. Data from [5–7]. Power consumption versus fs 22n for various published ADCs. We also show lines representing PS =12kTfs 22n and 104 times higher. Data from [5–7]. Sampling circuit. SDR implementation of a three channel radio for AIS band. Unfiltered digital signal including a signal at zero and a large blocker at 290kHz. Block diagram of an RF front-end based on a sampling downconversion filter. Implementation of the filter in the sampling downconversion unit. Chip photo of the sampling downconversion filter (a) and test board (b). Measured filter response, single-ended output and differential output. BWch is the anticipated channel width. Measured constellation diagram when receiving a 64QAM modulated signal. Shannon beats Moore. Source Rabaey [1]. Growth in Algorithmic Complexity vs Progress in VLSI, Design and Battery Technologies. VLSI Design Space (Source Flynn et. al. [5]). The decreasing stage size. Sea of DSP message passing platform from Philips Semiconductors. Multi-processor architecture shared memory architecture from Philips Semiconductors.

31 32 37 37 38 39 39 40

43

44 45 49 51 51 52 53 54 55 60 61 63 64 67 68

List of Figures

4.7 4.8 4.9 4.10 4.11 4.12 4.13 4.14 4.15 5.1 5.2 5.3 5.4 5.5 5.6 6.1 6.2 6.3 6.4 6.5 6.6 6.7 6.8 6.9 6.10 6.11 6.12 6.13 6.14 6.15 7.1 7.2

xiii

Embedded memory content in SOC is increasing rapidly. 70 Volatile Memory is shifting from static to dynamic memories. (Source [12]). 71 CPU vs Memory Speed Trends. Source: Hynix (Source [13]). 72 Evolution of Interconnect Schemes. 72 Evolution of NOC as intra-chip interconnect as well as an interchip interconect. 73 Evolution of Interconnect Protocols. 74 Abstracting IP Functions from System. 74 Trends in power consumption components. Source Nam Sung Kim et. al. [16]. 75 Multiple Voltage Domains. 77 Radio system overview. 83 Multi-path propagation. 85 Dynamic MIPS usage. 88 Hardware multiplexing on LeoCore DSPs. 88 OFDM processing flow. 92 LeoCore basic architecture. 96 Conceptual Block Diagram of a Radio Receiver. 104 Software Radio Architecture. 104 Superheterodyne Receiver Architecture. 106 Zero-IF Receiver Architecture. 106 Low-IF (near zero) Receiver Architecture. 107 High-IF (could be near RF) Receiver Architecture. 107 Figure-Of-Merit and Resolution vs. Bandwidth. 110 Required ADC Resolution vs. Bandwidth. 111 Generic Reconfigurable Σ∆ ADC. 113 Multi-standard Receiver. 114 Reconfigurable SC Modified Cascaded Σ∆ ADC. 115 SNDR vs. Input Signal. 115 4th order Continuous-Time Bandpass Sigma-Delta ADC. 117 Sigma-Delta Pipelined ADCs Array. 118 CT Sigma-Delta Pipelined ADCs array. 119 (a) Multiple parallel transceivers for each standard, versus (b) one flexible transceiver for multiple standards. 125 Simplified block diagram of a flexible software-defined 127 receiver with digital control of a reconfigurable front-end.

xiv

RADIO DESIGN IN NANOMETER TECHNOLOGIES

7.3 7.4

7.5 7.6 7.7 7.8 7.9 7.10 7.11 7.12 7.13 7.14 8.1 8.2 8.3 8.4 8.5 8.6 8.7 8.8 8.9 8.10 8.11

Comparison of performance of ∆Σ and pipelined A/D converters. Changing the resolution and bandwidth of a pipelined A/D converter by switching in/out stages and by changing the sampling rate. Reconfiguring an OTA by switching in/out different substages (different sizes, currents or capacitors. Basic Block Diagram of a ∆Σ modulator. SNDR vs. OSR for different ∆Σ A/D converter topologies. The Leslie-Singh architecture with discrete-time loop filter and digital reconstruction filter. Principle schematic of the tuning of the digital filter (implemented in the DSP block). (a) Structure of the digital IIR tuning filter, and (b) impact on the SFDR by tuning the digital filter coefficients. Circuit schematic of the pipelined quantizer used in the A/D converter. Circuit schematic of the loop filter used in the reconfigurable A/D converter. Chip photograph of a prototype multi-standard oversampling A/D converter in 0.18 µm CMOS technology. Simulated spectrum of the A/D converter before and after adapting the digital filter’s tuning coefficients. Different wireless scenarios and the connectivity options they provide. Simulation flow and interaction with the user of the frequency planning and budget tools. TACT components. Third order intermodulation in a non-linear system. Calculation of the k th order intercept point (IPk). Abstract model of a generic receiver architecture. Signal feedthrough and self-mixing. Effect of out-of-band interferers after going through a non-linear stage. Calculation of the most detrimental out-of-band interfering frequency bands. Algorithm to find a budget meeting specs. Minimum order of distortion components vs. the intermediate frequency band within which they fall.

128

129 129 130 131 132 133 134 135 136 137 138 146 150 150 153 154 156 157 160 161 164 167

List of Figures

8.12 8.13 9.1 9.2 9.3 9.4 9.5 9.6 9.7 9.8 9.9 9.10 9.11 9.12 9.13 9.14 9.15 9.16 10.1 10.2 10.3

10.4

10.5 10.6 10.7 10.8

Zero IF receiver architecture. Signal levels along the blocks for WCDMA and WLAN for a typical TACT run. Full-chip ESD protection network. Schematic of an active clamp. Cross-sections of substrate and N-well bottom diodes. ESD protection level vs. PN junction width. Interconnect routing configurations for an N-well top diode. Schematics of wide-band common-emitter and commonbase amplifiers. Schematic of a common-source narrowband LNA. Schematic of a dual-band LNA. Tuned ESD protection circuits. Protection circuits’ response to a 500 V CDM discharge. Cross-sections of floating-body, grounded-gate NFETs. Off-state impedance of SiGe HBT and dual-diode protection circuits. LNA test circuit. Six ESD protection strategies. T-coil based ESD protection circuit. Combined TLP/RF measurement system. Typical power amplifier schematic. (a) Conventional cascode amplifier. (b) Self-biased cascode amplifier [14]. (a) Fixed-bias cascode amplifier. (b) Collector and emitter voltage waveforms for fixed-bias cascode amplfier. (c) RF-driven cascode amplifier. (d) Collector and emitter voltage waveforms for the RF-driven cascode amplifier. (a) Schematic of a two stages single-ended CMOS power amplifier. (b) Simulated output power and power gain of the amplifier at 24GHz. A fully integrated differential SiGe PA with transformerbased matching network and on-chip balun [19]. Doubly-balanced transceiver front-end topology based on 90◦ and 180◦ couplers [23]. (a) Branch-line coupler. (b) Lange coupler. Conceptual schematic and layout of a 4-stage PA coupled through a distributed active transformer [26].

xv 168 169 174 174 176 177 178 179 180 181 182 183 184 185 185 186 188 189 195 197

198

199 201 203 203 205

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RADIO DESIGN IN NANOMETER TECHNOLOGIES

10.9 10.10 10.11 10.12 10.13 10.14 10.15 10.16

11.1

11.2 11.3 11.4 11.5 11.6 11.7 11.8 11.9 11.10 11.11 11.12 11.13

11.14 12.1 12.2 12.3

A generic slab inductor structure. EM Simulations showing the quality factor for different inductance values. E6-segement equivalent circuit for modeling the distributed transformer. Basic Differential Stage. Power combining in time domain. Pout, Gain and PAE v.s. Pin. Simulated 1-dB compression point versus frequency. Self-shielded monolithic transformer used in the distributedactive-transformer DAT-based power amplifier reported in [11]. Inductor π-model. Cox:tg L is the total capacitance from the inductor trace to ground and Cox:tt L is the total turnto-turn capacitance. Layout of symmetrical inductors. Layout of spiral inductors. Layout of spiral inductors, showing design parameters. (a) Electric and magnetic substrate losses without shield. (b) Magnetic (eddy) substrate losses with shield. Cross-section of microstrips on-chip and their capacitances. Capacitance ratios versus width, w. (t = 3µm, h = 6µm.)
Capacitance ratio of Cgt versus spacing between wires, s. (h = 6µm, and w = 10µm.) Main window of Indentro. Graphic view of technology file. A photograph of two of the inductors. The skating marks from the probes are clearly visible. Comparison between Indentro with FastHenry, and 1port and 2-port measurements. Tuning characteristic for three measured chips at 1.0V and 1.3V supply. Dashed lines is the simulated tuning characteristic. Simulated tuning characteristic at 1.0V and 1.3V supply with and without the fringe capacitances. Data rates for current and future radios. Mobile frequency spectrum. Power spectral density of a PLL output signal.

206 209 210 210 212 212 213

213

218 219 219 220 224 225 228 229 231 232 235 236

237 238 242 244 247

List of Figures

xvii

12.4

Spectrum analyzer output displaying the carrier phase noise. 250

12.5

Impact of LO close-in and far-out phase noise on the receiver.

253

12.6

Effect of phase noise on QPSK signal.

254

12.7

Typical transmitter frequency mask.

255

12.8

The effect of oscillator phase noise sidebands on the modulated sub-carrier in OFDM systems.

257

12.9

LPF types: a) Passive LPF, b) Active LPF.

259

12.10

PLL phase noise example showing contribution of different PLL sub-circuits. (A. Maxim, Silicon Labs Inc.)

261

a) Average charge pump current vs. input phase error at the phase detector. b) Time domain representation of charge pump output.

262

a) Charge pump up and down current at arbitrary phase offset showing the leakage effect. b) Charge pump output under lock condition.

263

Charge pump linear phase analysis showing locking under leakage condition.

264

12.14

Reference spur level as a function of leakage current.

265

12.15

a) PLL up and down currents under mismatch condition. b) PLL output current in lock condition.

266

PLL linear phase plot under different current mismatch conditions.

268

Reference spur level as a function of % mismatch in charge pump current.

269

(a) A digitally calibrated VCO to mitigate reduced tuning range due to limited voltage headroom (b) Unit coarse tuning cell.

270

Reduced effective tuning voltage range of a digitally calibrated VCO.

271

12.20

Block diagram of an analog amplitude controlled VCO.

271

12.21

Block diagram of a digital amplitude controlled VCO.

272

12.22

Circuit level implementation of (a) analog and (b) digital amplitude controlled deep-submicron VCOs.

273

Typical DDFS with associated word truncation points and spur sources.

274

12.11

12.12

12.13

12.16 12.17 12.18

12.19

12.23

xviii 12.24

12.25 12.26 12.27 12.28 12.29 12.30 12.31

13.1 13.2 13.3 13.4 13.5 13.6 13.7 13.8 13.9 13.10 13.11 13.12 13.13 13.14

RADIO DESIGN IN NANOMETER TECHNOLOGIES

A Σ∆DDFS with a lowpass noise shaper before the amplitude LUT and a bandpass noise shaper before the DAC. Associated noise shaping functions and NTF zeros are shown below the DDFS. a) Basic architecture of fractional-N PLL, b) Fractional division example, N=4.25. Σ∆ fractional-N synthesizer. Third-order Σ∆ modulator block diagram. Noise Spectrum for 3rd order Σ∆ MASH modulator. Block diagram of a frequency discriminator controlled ADPLL. Block diagram of an ADPLL utilizing a DCO. Typical DCO architectures utilizing a) programmable LC tank circuit b) programmable delay line via unit delay cells. A typical design cycle can take from 6 to 9 months. The price of mask sets are increasing exponentially with every new process generation[1]. An 802.11a/b/g WLAN radio transceiver. (a) transciver architecture, (b) chip photo. Texas Instruments Bluetooth transceiver [3]. The routing between the LNA and mixer form part of the LNA resonant tank Example of a QFN package [4]. Unit cell that provides a large capacitance per µm2 and metal density fill. The dummy blocking layers are used to prevent dummy patterns from being added to special areas. The p-implant blocking layer is used to create high resistivity substrate regions. The die seal used is a staggered die seal, designed to minimize the noise coupling in the chip. The reticle is used to provide the stepper with an image large enough to allow for accurate steps. Being self aware means that the block knows how well it is performing, by measuring its input and output Schematic of an RF detector. The RF detector can be calibrated against the PA to get accurate amplitude measurements.

276 278 279 280 281 282 283

283 289 290 291 294 296 298 298 301 302 303 304 306 307 307

List of Figures

To measure the compression point of the DUT, sweep the output power of the PA. 13.16a To measure the IQ imbalance, use both receiver basebands. 13.16b To measure one baseband, use both ADCs and DDS from the transmitter. 13.17 Once the cause of the impairments are found, circuit techniques can be used to close the calibration loop. 13.18 Through self awareness, the LNA knows that the gain has shifted down by 100MHz, and can retune its tanks to move it back. 13.19 The threshold and overload points are directly related to the input sensitivity and maximum input power. 13.20 A system employing self calibration in each block to maximize performance while minimizing power consumption.

xix

13.15

308 309 309 310

311 313

313

List of Tables

3.1 3.2 3.3 3.4 5.1 5.2 5.3 5.4 5.5 6.1 6.2 6.3 6.4 7.1 7.2 7.3 7.4 8.1 8.2

N, fs pairs fulfilling our requirement criterion. Requirements of ISM receiver. Non-zero coefficient multiplication and summation (S) sequence for the filter implementation shown in Fig. 3.13. Measured data of the sampling downconversion filter for two different sampling frequencies. FFT computation complexity for different OFDM standards OFDM algorithm profiling Computation complexity for WCDMA-FDD and HSDPA WCDMA algorithm profiling FEC algorithms usage in common standards Current and Future Radio Architectures ADCs with Outstanding Performance Enabling Technologies and ADC Architectures for SDR/SR Performance Summary of the Reconfigurable Σ∆Modulator 116 Different wire standards and some basic ADC requirements. Topology of the reconfigurable converter in the different modes. Summary of results for the different modes of the prototype chip design. Distribution of power consumption over the different blocks in the wideband mode. Execution time results. Summary of the WCDMA (TDD) and WLAN(802.11b) RF specifications.

xxi

43 49 52 54 90 91 94 95 99 105 109 112

124 137 138 139 165 166

xxii 8.3 8.4 8.5 9.1 9.2 9.3 9.4 10.1 10.2 10.3 11.1 11.2 11.3 11.4 12.1 12.2 12.3 12.4 13.1

RADIO DESIGN IN NANOMETER TECHNOLOGIES

Summary of the receiver specs for WCDMA (TDD) and WLAN (802.11b). Parameter distribution for the proposed WCDMA/WLAN multi-standard receiver. Specifications and performance of a typical run for a WCDMA/WLAN multi-standard receiver. Measurement results for 3 UWB LNAs. Measurement results for the dual-band LNA. Measurement results for the six LNA test circuits. Failure current values obtained from TLP testing of the six LNAs. Example of inductance values and corresponding dimensions Equivalent circuit component values. Final Design Parameters. Constants: Modified Wheeler. Constants: Geometric mean distance (GMD). Constants: Data-fitted monomial expression. Octagonal Inductor Geometries Under Measurement. Multi-radio PLL frequencies and bandwidth Standard RX Frequency Range (MHz) TX Frequency Range. CMOS technology scaling trends (C. Sodini, RFIC2005). 246 Relation between integrated phase noise and rms phase error. RMS Phase Error. Relative spur attenuation level (dB) for 3rd and 4th order LPF relative to 2nd order LPF. Parameters to be measured for self awareness

168 169 170 179 182 187 188 208 210 211 221 221 222 234 245

257 260 306

Preface

As we move beyond third generation (3G) wireless, future handheld wireless devices will be able to access different wireless infrastructures, e.g. cellular, WLAN, WiMaX for a multitude of wireless services including voice, data and multimedia applications. As a result, the radio part of a chipset for such a device will be increasingly complex and challenging. Currently, commercial radio chips are designed in 0.18 and 0.13 micron CMOS technologies. Single chip solutions (radio plus digital baseband) are recently becoming available commercially for Bluetooth, WLAN and GSM. Soon, radio chips will be designed in nanometer (