TABLE OF CONTENTS

COVER

TITLE PAGE

COPYRIGHT
DEDICATION

PREFACE

REFERENCES

ACKNOWLEDGMENT

PART I: EM IMAGE-BASED CHIPLESS RFID SYSTEM

CHAPTER 1: INTRODUCTION
1. 1.1 BARCODES AS IDENTIFICATION TECHNOLOGY
2. 1.2 RFID SYSTEMS
3. 1.3 BARCODES VERSUS RFID
4. 1.4 CHIPLESS RFID TAG FOR LOW-COST ITEM TAGGING
5. 1.5 CHIPLESS RFID SYSTEMS
6. 1.6 SPATIAL-BASED CHIPLESS RFID SYSTEM
7. 1.7 BOOK OUTLINE
8. REFERENCES
CHAPTER 2: EM IMAGING
1. 2.1 EM-IMAGING FUNDAMENTALS
2. 2.2 RANGE RESOLUTION
3. 2.3 CROSS-RANGE OR AZIMUTH RESOLUTION
4. 2.4 SYNTHETIC APERTURE RADAR (SAR) NECESSITY
5. 2.5 EM IMAGING FOR CONTENT CODING
6. 2.6 CONCLUSIONS
7. REFERENCES
CHAPTER 3: TINY POLARIZERS, SECRET OF THE NEW TECHNIQUE
1. 3.1 INTRODUCTION
2. 3.2 SWEETNESS OF DIFFRACTION
3. 3.3 STRIP-LINE POLARIZER
4. 3.4 MEANDER-LINE POLARIZER
5. 3.5 MULTIPLE POLARIZERS
6. 3.6 POLARIZER FABRICATION
7. 3.7 CONCLUSIONS
8. REFERENCES
CHAPTER 4: ATTRIBUTES OF EM POLARIZERS
1. 4.1 INTRODUCTION
2. 4.2 SUGGESTED STRUCTURES AS EFFECTIVE EM POLARIZERS
3. 4.3 CROSS-POLAR WORKING BASIS
4. 4.4 EFFECT OF HIGHLY REFLECTIVE ITEMS
5. 4.5 SECURE IDENTIFICATION
6. 4.6 BENDING EFFECT ON TAG PERFORMANCE
7. 4.7 CONCLUSION
8. REFERENCES
CHAPTER 5: SYSTEM TECHNICAL ASPECTS
1. 5.1 INTRODUCTION
2. 5.2 THE MM-BAND OF 60 GHZ
3. 5.3 READER ANTENNA
4. 5.4 CONCLUSIONS
5. REFERENCES
CHAPTER 6: SAR-BASED SIGNAL PROCESSING
1. 6.1 INTRODUCTION
2. 6.2 SAR MODES OF OPERATION
3. 6.3 SAR BLOCK DIAGRAM
4. 6.4 SAR-BASED SIGNAL PROCESSING
5. 6.5 TAG IMAGING RESULTS
6. 6.6 SYSTEM DOWNSIDES
7. 6.7 CONCLUSIONS
8. REFERENCES
CHAPTER 7: FAST IMAGING THROUGH MIMO-SAR
1. 7.1 INTRODUCTION
2. 7.2 CONVENTIONAL PHASED ARRAY ANTENNA
3. 7.3 MIMO-SAR SYSTEMS
4. 7.4 OPTIMIZATION
5. 7.5 MIMO-SAR RESULTS
6. 7.6 CONCLUSION
7. REFERENCES

PART II: ADVANCED TAG DETECTION TECHNIQUES FOR CHIPLESS RFID SYSTEMS

CHAPTER 8: INTRODUCTION
1. 8.1 RFID SYSTEMS
2. 8.2 REVIEW OF CHIPLESS RFID TAG DETECTION TECHNIQUES
3. 8.3 MAXIMUM LIKELIHOOD DETECTION TECHNIQUES
4. 8.4 CONCLUSIONS
5. REFERENCES
CHAPTER 9: CHIPLESS RFID TAG DESIGN
1. 9.1 INTRODUCTION
2. 9.2 SISO TAG DESIGN
3. 9.3 MIMO TAG DESIGN
4. 9.4 CONCLUSIONS
5. REFERENCES
CHAPTER 10: ML DETECTION TECHNIQUES FOR SISO CHIPLESS RFID TAGS
1. 10.1 INTRODUCTION
2. 10.2 SYSTEM MODELS–TIME DOMAIN
3. 10.3 SYSTEM MODELS–FREQUENCY DOMAIN
4. 10.4 SIMULATIONS
5. 10.5 EXPERIMENTAL SETUP
6. 10.6 RESULTS
7. 10.7 CONCLUSION
8. REFERENCES
CHAPTER 11: COMPUTATIONALLY FEASIBLE TAG DETECTION TECHNIQUES
1. 11.1 INTRODUCTION
2. 11.2 BIT-BY-BIT DETECTION METHOD
3. 11.3 TRELLIS-TREE-BASED VITERBI DECODING
4. 11.4 SIMULATION SETUP
5. 11.5 RESULTS
6. 11.6 CONCLUSIONS
7. REFERENCES
CHAPTER 12: SIGNAL PROCESSING FOR MIMO-BASED CHIPLESS RFID SYSTEMS
1. 12.1 INTRODUCTION
2. 12.2 MIMO DECOMPOSING TECHNIQUES
3. 12.3 TAG DETECTION IN MIMO
4. 12.4 EXPERIMENTAL SETUP
5. 12.5 SIMULATIONS
6. 12.6 RESULTS
7. 12.7 CONCLUSION
8. REFERENCE
CHAPTER 13: CONCLUSION FOR PART II
1. 13.1 SUMMARY OF THE PROPOSED TECHNIQUES IN PART II
2. 13.2 LIMITATIONS OF THE PROPOSED SYSTEM
3. 13.3 POTENTIAL APPLICATIONS
4. 13.4 FUTURE WORK AND OPEN ISSUES
5. REFERENCE
INDEX

END USER LICENSE AGREEMENT

List of Illustrations

CHAPTER 1: INTRODUCTION

Figure 1.1 Application areas of identification systems.
Figure 1.2 Data encoding limitation of a 1D barcode tag due to diffraction effect.
Figure 1.3 RFID general system structure.
Figure 1.4 Expected tag volume versus tag cost. Source: IDTechEx [1].
Figure 1.5 General classifications of chipless RFID systems.
Figure 1.6 Working basis of the frequency-domain chipless RFID systems.
Figure 1.7 Phase-domain-based chipless RFID tags.

CHAPTER 2: EM IMAGING

Figure 2.1 The precision comparison of two imaging systems: (a) conventional radar and (b) optical camera.
Figure 2.2 Reader footprint on tag structure.
Figure 2.3 Range resolution concept.
Figure 2.4 Slant- and ground-range resolutions.
Figure 2.5 Ground- and slant-range resolutions of the millimeter-wave chipless tag.
Figure 2.6 Required 3-dB beamwidth of reader antenna versus reading distance.
Figure 2.7 Antenna aperture size for 1° beamwidth.
Figure 2.8 Evolution of conventional radar toward SAR system through array antenna concept.
Figure 2.9 Azimuth resolution and required synthetic aperture length.
Figure 2.10 Pixelated tag and two different reading scenarios.

CHAPTER 3: TINY POLARIZERS, SECRET OF THE NEW TECHNIQUE

Figure 3.1 Reflection strength based on terrain roughness in earth imaging system [1].
Figure 3.2 Initial proposed tag structure based on earth imaging concept.
Figure 3.3 Backscattered signals from different types of strips; simulation result.
Figure 3.4 Geometry of diffraction by conductive strip on dielectric slab.
Figure 3.5 Copolar and cross-polar components of diffracted signals, linear scale.
Figure 3.6 Strip orientation for creating cross-polar components, L = 1.45, w = 0.2, ϵ = 2.55, h = 0.0127, all in millimeters.
Figure 3.7 Simulated copolar /cross-polar components of backscattered signal, single strip line, L = 1.45, w = 0.2, ϵ = 2.55, h = 0.0127, all in millimeters.
Figure 3.8 Meander line as transmission EM polarizer.
Figure 3.9 Multilayer meander-line structure for reflection EM polarizer.
Figure 3.10 Simulated copolar/cross-polar component of single-layer strip line and meander-line structure.
Figure 3.11 Final tag structure for data encoding purpose.
Figure 3.12 (a) Five strip lines with same length and (b) simulated copolar/cross-polar backscattered signals.
Figure 3.13 Simulated copolar/cross-polar components of backscattered signal.
Figure 3.14 Fabricated EM polarizers through photolithographic process.
Figure 3.15 (a) SATO printer, (b) printed strip lines, (c), and (d) printed meander lines.

CHAPTER 4: ATTRIBUTES OF EM POLARIZERS

Figure 4.1 System measurement setup: (a) printed strip lines, (b) printed meander lines, (c) whole system, and (d) reader antenna.
Figure 4.2 Measurement result for photolithographic fabricated tags.
Figure 4.3 Measurement result for printed tags with SATO.
Figure 4.4 Schematic block diagram of the chipless RFID system.
Figure 4.5 (a) Severe multipath interference scenario and (b) high clutter for the reading process.
Figure 4.6 Measurement result for multipath and high-clutter situations.
Figure 4.7 (a) Printed meander line tags attached to a plastic bottle of water and (b) measurement result.
Figure 4.8 An etched-out printed meander line tag attached to an aluminum can and (b) measurement result.
Figure 4.9 (a) NLoS reading scenario and (b) measurement process.
Figure 4.10 Measurement results for NLoS scenarios with pictures of some barriers.
Figure 4.11 Expected bending on tag length.
Figure 4.12 Different paper tubes with varying radii.
Figure 4.13 Relation between arc angle of attached tag and radius of objects.
Figure 4.14 System structure for bending effect measurement.
Figure 4.15 Measurement result based on different tag bending scenarios.

CHAPTER 5: SYSTEM TECHNICAL ASPECTS

Figure 5.1 Specific attenuation due to atmospheric gases [1].
Figure 5.2 Tag frequency versus skin depth in microns for various materials [9].
Figure 5.3 Kurz SECOBO® antennas [10].
Figure 5.4 Required HPBW of the antenna.
Figure 5.5 Design flowchart for array of DSPDs.
Figure 5.6 (a) Layout of a sample SIW resonator with via holes [24] and (b) photograph of prototype SIW resonator [33].
Figure 5.7 Printed dipole's structure and its dimensions, W_f = 0.37, F_L = 1.05, F_a = 0.55, W_a = 0.19, L_a=1, C_d = 0.2 and h = 0.127 (all dimensions in millimeters).
Figure 5.8 Chamfering effect on the impedance matching.
Figure 5.9 (a) Embedded dipole with tapered GND and (b) effect on impedance matching.
Figure 5.10 CST-generated 3D radiation pattern of double-side printed dipole (DSPD) antenna.
Figure 5.11 Simulated radiation pattern (E- and H-planes) of DSPD.
Figure 5.12 Simulated cross-polar level of single dipole (DSPD).
Figure 5.13 T-junction power divider.
Figure 5.14 T-junction power divider with (a) V-notch and (b) reactive stub.
Figure 5.15 Complete corporate feeding network of array.
Figure 5.16 The S-parameter of the corporate feeding network of array.
Figure 5.17 Transmission phase of different output ports (S₂₁ and S₃₁) versus frequency.
Figure 5.18 (a) Two adjacent dipoles for mutual coupling measurement and (b) simulation result.
Figure 5.19 Comparing physical sizes of the array antenna and V-type connector.
Figure 5.20 Extended CPW feedline and final array structure.
Figure 5.21 (a) Array and V-type connector for simulation and (b) reflection coefficient.
Figure 5.22 Percentage of errors in fabrication process.
Figure 5.23 Five DSPD arrays and highlighted parametrized sections of array.
Figure 5.24 Simulated S₁₁ and five measured return losses of sample arrays.
Figure 5.25 System setup for radiation pattern measurement.
Figure 5.26 Measured and simulated E-plane radiation pattern, co- and cross-polar radiation.
Figure 5.27 (a) Measurement setup for 1° accuracy and (b) measured and simulated HPBW of E-plane.
Figure 5.28 Measured gain and simulated feedline loss of array.

CHAPTER 6: SAR-BASED SIGNAL PROCESSING

Figure 6.1 SAR modes of operation: (a) spotlight mode and (b) strip map mode.
Figure 6.2 General block diagram of typical SAR-based system [2].
Figure 6.3 Image formation processing using RMA [2].
Figure 6.4 Photograph of 4-bit printed tag.
Figure 6.5 Raw SAR signal for a tag with (a) “1001” and (b) “1011.”
Figure 6.7 Image of 4-bit tags with 22 cm aperture size, (a) “1001” and (b) “1011.”
Figure 6.6 Four-bit printed tag and received cross-polar signals after signal processing.
Figure 6.8 EM image of the tag “1011” with (a)12 cm and (b) 17 cm aperture size.
Figure 6.9 Final and fundamental aperture length.
Figure 6.10 Eight-bit tag and its related signals, aperture size 24 cm.
Figure 6.11 Cross-polar EM image of tag with (a) 11 bits of data and aperture size 25.5 cm and (b) 17 bits of data and aperture size 29 cm.
Figure 6.12 Handheld reader with mechanically moving antennas.
Figure 6.13 Tag orientation: (a) correct angle of 45° and (b) misoriented tag angle of θ°.
Figure 6.14 Effect of tag orientation on received signal level.
Figure 6.15 System degradation due to tag misorientation effect.

CHAPTER 7: FAST IMAGING THROUGH MIMO-SAR

Figure 7.1 System structure of the proposed spatial-based approach.
Figure 7.2 MIMO-based antenna system and the equivalent sparse array antennas.
Figure 7.3 MIMO-based antenna and its equivalent virtual array antenna.
Figure 7.4 Relative phase shift between one particular Tx antenna and all Rx antennas.
Figure 7.5 MIMO-based antenna and its equivalent virtual array.
Figure 7.6 Conventional SAR and MIMO-SAR in a glance.
Figure 7.7 MIMO-based antenna for EM-image-based chipless RFID system.
Figure 7.8 Photographs of (a) printed 6-bit tag, (b) tag image through normal SAR, and (c) tag image through MIMO-SAR technique.
Figure 7.9 General block diagram of the GA.
Figure 7.10 Sample chromosome for the MIMO-SAR optimization, red values relate to Rx and black numbers show the Tx array.
Figure 7.11 Structure of population in GA.
Figure 7.12 Selection operator based on roulette wheel approach.
Figure 7.13 Suggested formula by Rahmat-Samii and Michielssen [15] for selection operator.
Figure 7.14 Suggested formula for selection operator with best result.
Figure 7.15 Multipoints crossover operator.
Figure 7.16 Final virtual array with 28.2 cm length and one missing element.
Figure 7.17 Final virtual array with 28.6 cm length and two missing elements.
Figure 7.18 Simulated received signal and the tag's image for (a) conventional SAR technique and (b) optimized MIMO system with 25 elements.
Figure 7.19 Simulated received signal and the tag's image for (a) conventional SAR technique, optimized MIMO system of (b) Sample 1 and (c) Sample 2.

CHAPTER 8: INTRODUCTION

Figure 8.1 A typical RFID system.

CHAPTER 9: CHIPLESS RFID TAG DESIGN

Figure 9.1 Tag types used in SISO and MIMO detection algorithm developments.
Figure 9.2 Printed tag.
Figure 9.3 Experimental setup.
Figure 9.4 Magnitude of the tag response for tag [1111].
Figure 9.5 T-junction power divider. (a) CST design; (b) fabricated power divider. TLX8 substrate with $c09-math-0006$ , $c09-math-0007$ and $c09-math-0008$ mm.
Figure 9.6 S-parameters of the power divider.
Figure 9.7 Monopole antenna. (a) CST design; (b) fabricated monopole).
Figure 9.8 Return loss of the monopole antenna.
Figure 9.9 Simulated radiation pattern of the monopole antenna.
Figure 9.10 Realized gain of the monopole antenna.
Figure 9.11 Spiral resonators. (a) CST design; (b) fabrication.
Figure 9.12 CST-generated resonator response.
Figure 9.13 Fabricated MIMO tag.
Figure 9.14 MIMO tag experiment.
Figure 9.15 Tag response for [1010].

CHAPTER 10: ML DETECTION TECHNIQUES FOR SISO CHIPLESS RFID TAGS

Figure 10.1 RFID system models.
Figure 10.2 Overview of chipless RFID system.
Figure 10.3 Proposed signal models.
Figure 10.4 Flowchart of the MATLAB simulation in conjunction with CST full-wave EM solver simulation.
Figure 10.5 A chipless tag coded with bits $c10-math-0273$ .
Figure 10.6 Experimental setup.
Figure 10.7 Interrogating signal in time and frequency domain.
Figure 10.8 Tag responses for $c10-math-0276$ with a guard-band.
Figure 10.9 Tag responses for $c10-math-0277$ without a guard-band.
Figure 10.10 DER versus SNR for 4-bit tag with 60 MHz guard-band.
Figure 10.11 DER versus SNR without a guard-band between resonator frequencies.
Figure 10.12 DER versus SNR for ML decoder 1.
Figure 10.13 Real and imaginary samples of the tag response [1111].
Figure 10.14 Frequency signature of tag type [1111].
Figure 10.15 DER versus SNR for ML decoder 2 with the presence of a guard-band.
Figure 10.16 DER versus SNR for ML decoder 2 without a guard-band.
Figure 10.17 DER versus SNR for ML decoder 2.
Figure 10.18 DER comparison for 8-bit tags.
Figure 10.19 DER verus SNR for ML decoder 3 with the presence of a guard-band.
Figure 10.20 DER versus SNR for ML decoder 3 without a guard-band.
Figure 10.21 DER versus SNR for ML decoder 3.
Figure 10.22 DER versus SNR for ML decoder 4 with the presence of a guard-band.
Figure 10.23 DER versus SNR for ML decoder 4 without a guard-band.
Figure 10.24 DER versus SNR for ML decoder 4.
Figure 10.25 Channel estimation samples when a guard-band is presented.
Figure 10.26 PDF of channel estimation when a guard-band is presented.
Figure 10.27 Channel estimation samples without a guard-band.
Figure 10.28 PDF of channel estimation without a guard-band.
Figure 10.29 DER comparison with a guard-band.
Figure 10.30 DER comparison without a guard-band.
Figure 10.31 Magnitude of the tag response for tag [1111].
Figure 10.32 DER versus SNR for likelihood-based detector 5 for 21–27 GHz backscattering tag.

CHAPTER 11: COMPUTATIONALLY FEASIBLE TAG DETECTION TECHNIQUES

Figure 11.1 Bit-by-bit detection for a tag having [1111].
Figure 11.2 Flowchart of bit-by-bit detection technique.
Figure 11.3 Operation of Trellis-tree-based Viterbi detection technique.
Figure 11.4 Viterbi decoding in a trellis tree.
Figure 11.5 Flow chart of trellis-tree-based Viterbi decoding.
Figure 11.6 Flowchart of the MATLAB simulation.
Figure 11.7 DER comparison for 10-bit tags.
Figure 11.8 Computation complexity comparison.

CHAPTER 12: SIGNAL PROCESSING FOR MIMO-BASED CHIPLESS RFID SYSTEMS

Figure 12.1 MIMO-based chipless RFID system.
Figure 12.2 MIMO tag.
Figure 12.3 MIMO tag operation overview.
Figure 12.4 MIMO tag experiment.
Figure 12.5 Tag response for [1010].
Figure 12.6 Flowchart of the MATLAB simulation.
Figure 12.7 Flowchart of the MATLAB simulation.
Figure 12.8 Interrogating signal in time domain.
Figure 12.9 Two-sided PSD of the interrogating signal.
Figure 12.10 Received signal at the tag.
Figure 12.11 Filter response of a spiral resonator.
Figure 12.12 Two-sided PSD of the tag-modulated signals (Tx1 and Tx2).
Figure 12.13 Tag-modulated signals (Tx1 and Tx2) in time domain.
Figure 12.14 Channel realizations.
Figure 12.15 Received signals at the two Rx antennas of the reader.
Figure 12.16 Actual and the estimated Tx1.
Figure 12.17 Actual and the estimated Tx2.
Figure 12.18 Combined tag response.
Figure 12.19 Combined tag response for 100 iterations.
Figure 12.20 BER of the proposed system versus SNR.
Figure 12.21 Noise performance of the proposed system versus SISO counterpart.
Figure 12.22 CST-generated tag response for a branch having [1111] tag bits.
Figure 12.23 Comparison of DER performances for 6 bit tags.

List of Tables

CHAPTER 1: INTRODUCTION

Table 1.1 Barcode, QR codes, and RFID [8, 9]

CHAPTER 4: ATTRIBUTES OF EM POLARIZERS

Table 4.1 Multiple Barrier
Table 4.2 Dimensions of Paper Tubes and Some Well-Known Items

CHAPTER 5: SYSTEM TECHNICAL ASPECTS

Table 5.1 Available Spectrum on 60 GHz Band
Table 5.2 Technical and Operational Requirements of the Reader Antenna
Table 5.3 Summary of Dielectric Parameters of TLX-8
Table 5.4 3-dB Beamwidth of a Single DSPD in H-Plane
Table 5.5 Fabrication Variation
Table 5.6 Simulated and Measured HPBW in E-Plane

CHAPTER 6: SAR-BASED SIGNAL PROCESSING

Table 6.1 Synthetic Aperture Size and Image Resolution

CHAPTER 7: FAST IMAGING THROUGH MIMO-SAR

Table 7.1 The MIMO-Based Advantages

CHAPTER 8: INTRODUCTION

Table 8.1 Comparison of Communication System with a Chipless RFID System

CHAPTER 9: CHIPLESS RFID TAG DESIGN

Table 9.1 Simulation Parameters
Table 9.2 Tag Types Given by Resonator Combinations

CHAPTER 10: ML DETECTION TECHNIQUES FOR SISO CHIPLESS RFID TAGS

Table 10.1 Simulation Parameters
Table 10.2 DER Comparison for Different Detection Methods
Table 10.3 Likelihood for each tag type

CHAPTER 11: COMPUTATIONALLY FEASIBLE TAG DETECTION TECHNIQUES

Table 11.1 Simulation Parameters

CHAPTER 12: SIGNAL PROCESSING FOR MIMO-BASED CHIPLESS RFID SYSTEMS

Table 12.1 An Example of a Table
Table 12.2 Simulation Parameters
Table 12.3 Simulation Parameters

CHAPTER 13: CONCLUSION FOR PART II

Table 13.1 Technical Specifications of Raspberry Pi 2 Model B

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, scanning, or otherwise, except as permitted under Section 107 or 108 of the 1976 United States Copyright Act, without either the prior written permission of the Publisher, or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center, Inc., 222 Rosewood Drive, Danvers, MA 01923, (978) 750-8400, fax (978) 750-4470, or on the web at www.copyright.com. Requests to the Publisher for permission should be~addressed to the Permissions Department, John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030, (201) 748-6011, fax (201) 748-6008, or online at http://www.wiley.com/go/permission.

Limit of Liability/Disclaimer of Warranty: While the publisher and author have used their best efforts in preparing this book, they make no representations or warranties with respect to the accuracy or completeness of the contents of this book and specifically disclaim any implied warranties of merchantability or fitness for a particular purpose. No warranty may be created or extended by sales representatives or written sales materials. The advice and strategies contained herein may not be suitable for your situation. You should consult with a professional where appropriate. Neither the publisher nor author shall be liable for any loss of profit or any other commercial damages, including but not limited to\break special, incidental, consequential, or other damages.

For general information on our other products and services or for technical support, please contact our Customer Care Department within the United States at (800) 762-2974, outside the United States at (317)572-3993 or fax (317) 572-4002.

Wiley also publishes its books in a variety of electronic formats. Some content that appears in print may not be available in electronic formats. For more information about Wiley products, visit our web site at www.wiley.com.

Names: Karmakar, Nemai Chandra, 1963- author. | Zomorrodi, Mohammad, 1973- author. | Divarathne, Chamath, 1983- author.

Title: Advanced chipless RFID : MIMO-Based Imaging at 60 GHz- ML Detection / by Nemai Chandra Karmakar, Mohammad Zomorrodi, Chamath Divarathne.

Description: Hoboken, New Jersey : John Wiley & Sons, Inc., [2016] | Series: Wiley series in microwave and optical engineering ; 1187 | Includes bibliographical references and index.

Classification: LCC TK6570.I34 K364 2016 | DDC 621.3841/92- dc23 LC record available at https://lccn.loc.gov/2016014411

Shipra, Antara, and Ananya Karmakar
Fathemeh Sajjadidokht, Mohammadkasra, and Zoha Zomorrodi
Navarathne Banda and Dayani Chandramali

PREFACE

The author's group has developed various chipless RFID tags and reader architectures at 2.45, 4–8, 24, and 60 GHz. These results were published extensively in the form of books, book chapters, refereed conference and journal articles, and finally, as patent applications. However, there is still room for improvement of chipless RFID systems. In this book, we proposed advanced techniques of chipless RFID systems that supersede their predecessors in signal processing, tag design, and reader architecture.

The book introduces a few novel and advanced-level high-capacity data encoding and throughput improvement techniques for fully printable multibit chipless RFID tags and reader systems, respectively. These techniques enhance data content capacity of tags and perform reliable tag detection for readers at the instrumentation, scientific, and medical (ISM) frequency bands 2.45, 24, and 60 GHz. First, a comprehensive review of existing chipless RFID tags provides the state of the art in the field and exposes impediments for commercial success. The limiting factors for commercialization of reported chipless RFID tags are (i) printing errors, (ii) degradation of tag performance on low-grade laminates, (iii) low data capacity, (iv) errors in tag reading in industrial environment, (v) reading reliability, and (vi) read range. This book addresses these limitations and provides solutions with an image-based tag design and advanced signal processing techniques.

The book provides the details of the new approaches – electromagnetic (EM) imaging, high-capacity data encoding, and robust tag detection techniques. In the introduction chapter first, a comprehensive review of the available and reported chipless RFID systems is presented. Then, their above-mentioned impediments for commercial success are analyzed. The analysis shows that the conventional techniques used for chipless RFID tag encoding and detection do not address the challenges imposed by commercial grade tags and reader systems. This encourages the researchers for new techniques and approaches in this field.

The book is divided into two main parts. Part I of the book, “EM Image-Based Chipless RFID System,” introduces the novel EM imaging concept for data extraction from a 60-GHz chipless RFID tag. Part II “Advanced Tag Detection Techniques for Chipless RFID Systems” presents smart tag detection techniques for existing chipless RFID systems and an innovative MIMO-based tag detection technique for high content capacity and zero guard-band tag detection. These approaches have been fully developed and tested in Monash Microwave, Antenna RFID and Sensor Research Group (MMARS) at Monash University.

In Part I of the book, the fundamental of EM imaging at millimeter-wave band 60 GHz for data extraction is introduced followed by the EM imaging through synthetic aperture radar (SAR) technique. It is shown that the millimeter-wave EM imaging has significant potentials for commercialization of chipless RFID. The EM imaging technique exploits advantages of RFID systems including their flexible non-line-of-sight (NLoS) operation and high data capacity benefit. Moreover, the proposed EM imaging technique inherits low-cost advantages and fully printable features of the barcodes on low-grade packaging materials. The downside of the conventional SAR-based EM imaging technique, requirement for physical movement of the reader antenna, is addressed by the new idea of MIMO-SAR technique. With the proposed MIMO-based EM imaging, no relative movement of the reader and tag is required hence very fast tag imaging is achievable. Finally, the MIMO approach is optimized through global genetic approach for minimum hardware complexity and to introduce a complete solution for chipless RFID system. In this pursuit, the system elements and technical requirements are discussed in details. The proposed approach to the EM imaging technique enhances the content capacity of the chipless systems to a commercial level, for example, EPC Global Class 1 Generation 2 with 64 data bits.

The main emphasis for Part II of the book is to introduce a few new smart tag detection techniques for chipless RFID systems. Researchers were mainly focusing on improving the RFID reader architecture [1, 2] and the chipless tag design in conventional approaches [3] and paying less attention to signal processing. As a result, most signal processing techniques being used in chipless RFID systems are primitive and should further be investigated. The first part of Part II focuses on advanced signal processing techniques that significantly improve the tag detection rate and tag reading range for the existing reader architecture [1] and tag design [4]. In addition, the proposed techniques allow removing the guard band presented in frequency-domain tags allowing the spectral efficiency to be improved. As a result, data capacity of the frequency-domain tags can be improved. Maximum-likelihood (ML)-based detection techniques have shown improved performances in communication systems compared to reported techniques such as threshold-based detection techniques [5]. The motivation for this work is to apply the ML detection techniques for chipless RFID tag detection so that the existing RFID system would perform better. One limitation of likelihood-based techniques is its exponential increase in computation complexity with higher number of data bits. Two computationally feasible tag detection techniques have been introduced to overcome this challenge. With these new tag detection techniques, computation complexity only increases linearly with the number of data bits. The second part of Part II presents a novel MIMO-based chipless RFID system and required tag detection techniques that can be used to improve the spectral efficiency, hence increasing data bit capacity.

We hope that the book will contribute significantly to the field of chipless RFID removing many practical barriers for commercialization of the technology.

Nemai Chandra Karmakar
Mohammad Zomorrodi
Chamath Divarathne
Melbourne
November 2015

REFERENCES

1. N.C. Karmakar, R. Koswatta, P. Kalansuriya and R. E-Azim, Chipless RFID Reader Architecture, Artech House Publishing, 2013.
2. R.V. Koswatta and N.C. Karmakar, “A Novel Reader Architecture Based on UWB Chirp Signal Interrogation for Multiresonator-Based Chipless RFID Tag Reading,” IEEE Transactions on Microwave Theory and Techniques, vol. 60, no. 9, pp. 2925–2933, 2012.
3. R. Rezaiesarlak, and M. Manteghi, Chipless RFID, Design Procedure and Detection Techniques, Springer, USA, 2015.
4. S. Preradovic and N.C. Karmakar, Multi-Resonator-Based Chipless RFID, Springer, USA, 2012.
5. R. Koswatta and N.C. Karmakar, “Moving Average Filtering Technique for Signal Processing in Digital Section of UWB Chipless RFID Reader,” Proc. 2010 Asia Pacific Microwave Conference, Yokohama, Japan, December 7–10, 2010.

ACKNOWLEDGMENT

The book is the outcome of two PhD level thesis works under the supervision of the first author. The PhD scholarship was supported by the Australian Research Council (ARC) Discovery Project grant DP110105606: Electronically Controlled Phased Array Antenna for Universal UHF RFID Applications. Therefore, the support from ARC is highly acknowledged. The editor-in-chief of Wiley Mr. Brett Kurzman, Editor, Global Research, Professional Practice and Learning, Wiley and Mr. Alex Castro, Senior Editorial Assistant of Wiley were very supportive from the inception of the book project to the end of production. Their support is highly acknowledged. The two student authors were cosupervised by Professors Jeff Walker and Jamie Evans of Monash University. Their valuable suggestions and technical assistance are also acknowledged. During the course of the research work, the team members of the authors' research group, Monash Microwave, Antenna, RFID, and Sensor (MMARS) Laboratory of Monash University, were very supportive to the PhD projects. The supports from the electronics and mechanical workshops of ECSE department of Monash University were instrumental for the research outcomes that are produced in the book.

The family members of the Authors had to endeavor their absence during this research. Their support and companionship are gratefully acknowledged.

Nemai Karmakar
Mohammad Zomorrodi
Chamath Divarathne
Melbourne
November 2015

ADVANCED CHIPLESS RFID

MIMO-Based Imaging at 60 GHz-ML Detection

PREFACE

REFERENCES

ACKNOWLEDGMENT

PART I
EM IMAGE-BASED CHIPLESS RFID SYSTEM