NUNO BORGES CARVALHO, PHD, is a Full Professor at DETI, University of Aveiro, a Senior Research Scientist with the Institute of Telecommunications, and an IEEE Fellow. He is associate editor of the IEEE Microwave Magazine and Cambridge Wireless Power Transfer Journal and former associate editor of the IEEE Transactions on Microwave Theory and Techniques. Dr. Borges Carvalho belongs to the ADCOM of IEEE-MTT and is the Vice-Chair of the URSI Commission A (Metrology Group).APOSTOLOS GEORGIADIS, PHD, is Honorary Associate Professor at Heriot-Watt University, Edinburgh, UK. He is Vice-Chair of EU COST Action IC1301 on Wireless Power Transfer for Sustainable Electronics. He is former Editor-in-Chief of Cambridge Wireless Power Transfer Journal and former Associate Editor of the IEEE Microwave Wireless Components Letters and IET Microwaves Antennas and Propagation journals. He is Chairman of URSI Commission D Electronics and Photonics and a Distinguished Lecturer of IEEE Council on RFID (CRFID).

• List of Figures xiiiList of Contributors xxxiiiPreface xxxviiAcknowledgments xxxix1 Textile-Supported Wireless Energy Transfer 1Miroslav Cupal, Jaroslav Láčík, Zbynĕk Raida, Jan Špůrek, and Jan Vélim1.1 Introduction 11.2 Textile-Coated Single-Wire Transmission Line 31.3 Textile-Integrated Components 61.3.1 Fabrication of the Top Conductive Layer and the Bottom One 81.3.2 Fabrication of Conductive Vias of Side Walls 81.4 In-Vehicle Wireless Energy Transfer 151.5 Summary 24References 252 A Review of Methods for the Electromagnetic Characterization of Textile Materials for the Development of Wearable Antennas 27Caroline Loss, Ricardo Gonçalves, Pedro Pinho, and Rita Salvado2.1 Introduction 272.2 Electromagnetic Properties of Materials 292.2.1 Conductive Fabrics 292.2.2 Dielectric Fabrics 312.3 Dielectric Characterization Methods Applied to Textile Materials and Leather: A Survey 322.3.1 Resonant Methods 332.3.1.1 Cavity Perturbation Methods 332.3.1.2 Microstrip Resonator Patch Method 352.3.1.3 Microstrip Resonator Ring Method 352.3.1.4 Microstrip Patch Sensor 352.3.1.5 Agilent 85070E Dielectric Measurement Probe Kit 392.3.1.6 Summary of the Characterization of Textile Materials by Resonant Methods 402.3.2 Nonresonant Methods 402.3.2.1 Parallel Plate Method 402.3.2.2 Free Space Methods 412.3.2.3 Planar Transmission Lines Methods 442.3.2.4 Summary of the Characterization of Textile Materials by Nonresonant Methods 462.4 Some Factors that Affect the Measurement of Dielectric Properties of Textiles 462.4.1 Influence of the Moisture Content 462.4.2 Influence of the Material Anisotropy 472.4.3 Influence of the Bulk Porosity 472.4.4 Influence of the Surface Features 482.5 Conclusions 48Acknowledgments 50References 503 Smart Beamforming Techniques for “On Demand” WPT 57Diego Masotti, Mazen Shanawani, and Alessandra Costanzo3.1 Introduction 573.2 Basics of Time-modulated Arrays 613.3 Nonlinear/Full-Wave Co-simulation of TMAS 633.4 Two-Step Agile WPT Strategy 643.4.1 Localization Step 653.4.2 Power Transfer Step 663.5 Simulation Results 683.5.1 Localization Step 683.5.2 Power Transfer Step 693.6 Measured Results 733.7 TMA Architecture for Fundamental Pattern Steering 763.8 Conclusion 81References 824 Backscatter a Solution for IoT Devices 85Daniel Belo, Ricardo Correia, Marina Jordao, Pedro Pinho, and Nuno B. Carvalho4.1 Backscatter Basics 854.1.1 Different Backscatter Sensors Development 874.1.2 Backscatter with WPT Capabilities 874.1.3 High-Order Backscatter Modulation 884.1.4 Modulated High-Bandwidth Backscatter with WPT Capabilities 894.2 An IoT-Complete Sensor with Backscatter Capabilities 904.2.1 System Description 914.2.2 Digital Component 924.2.3 Measurements 944.3 The Power Availability for These Sensors 974.3.1 Electronically Steerable Phased Array for Wireless Power Transfer Applications 984.3.2 Wireless Energy Receiving Device 1014.3.3 Experimental Results 1044.4 Characterization of High-Order Modulation Backscatter Systems 1074.4.1 Characterization System 1074.4.2 Measurements 110References 1145 Ambient FM Backscattering Low-Cost and Low-Power Wireless RFID Applications 117Spyridon N. Daskalakis, Ricardo Correia, John Kimionis, George Goussetis, Manos M. Tentzeris, Nuno B. Carvalho, and Apostolos Georgiadis5.1 Introduction 1175.2 Ambient Backscattering 1205.2.1 Ambient FM Backscattering 1225.2.2 Binary Modulation Tag 1245.2.3 4-PAM Tag 1255.2.4 Binary Telecommunication Protocol 1275.2.5 4-PAM Telecommunication Protocol 1295.2.6 Receiver 1295.2.7 Software Binary Receiver 1305.2.8 Software 4-PAM Receiver 1325.2.9 Experimental and Measurement Results 1325.3 Conclusions 138Acknowledgments 139References 1396 Backscatter RFID Sensor System for Remote Health Monitoring 145Jasmin Grosinger6.1 Introduction 1456.2 On-Body System 1466.2.1 Body Model 1466.2.2 Antennas 1496.2.2.1 Monopole Antennas 1496.2.2.2 Patch Antennas 1516.3 Radio Channel 1526.3.1 Measurement Setup 1536.3.2 Comparison of Simulations and Measurements 1546.3.3 Measurement Results 1566.3.3.1 Antenna Matching 1566.3.3.2 Channel Gain 1576.4 System Performance 1596.4.1 Forward Link 1626.4.1.1 System Example 1656.4.2 Backward Link 1666.4.2.1 System Example 1666.5 Conclusions 168Acknowledgments 169References 1707 Robotics Meets RFID for Simultaneous Localization (of Robots and Objects) and Mapping (SLAM) – A Joined Problem 175Antonis G. Dimitriou, Stavroula Siachalou, Emmanouil Tsardoulias, and Loukas Petrou7.1 Scope 1757.2 Introduction 1767.3 Localization of RFID Tags – Prior Art 1827.3.1 Multipath in Passive RFID Systems 1847.3.2 Representative Localization Techniques 1857.3.2.1 Angle of Arrival 1857.3.2.2 Received Signal Strength – Bayes’ Theorem and Conditional Probability 1877.3.2.3 Fingerprinting – “Landmarc” 1897.3.2.4 Holographic Localization 1907.3.2.5 Other Methods 1927.3.3 Analysis of Prior Art 1947.4 A Brief Introduction in SLAM/Localization Techniques 1957.4.1 Introduction to Localization, Mapping, and SLAM 1967.4.2 Mathematical Formulation of SLAM 1977.4.3 Probabilistically Solving SLAM 1987.4.4 Space Representation in SLAM 2017.4.5 SLAM Algorithm Selection 2027.4.5.1 What are the Robot’s Sensors? 2027.4.5.2 Which is the Environmental Morphology? 2037.4.5.3 How Will the Generated Map Be Utilized? 2037.4.6 SLAM/Localization and RFID Localization Issues 2047.5 Prototype – Experimental Results 2067.5.1 Equipment 2067.5.2 Methodology 2087.5.2.1 Phase 1 2087.5.2.2 Phase 2 2097.5.3 Results 2127.6 Discussion 216Acknowledgments 218References 2188 From Identification to Sensing: Augmented RFID Tags 223Konstantinos Zannas, Hatem El Matbouly, Yvan Duroc, and Smail Tedjini8.1 Introduction 2238.2 Generic RFID Communication Chain 2268.2.1 RFID Sensor Tag 2268.2.2 RFID Data Capture Level 2288.2.3 RFID Tag Process Level 2298.2.4 RFID Communication Channel 2318.2.5 RFID Reader Process Level and RFID Reader 2328.3 RFID Sensor Tags: Examples from Literature or Commercially Available 2338.3.1 Examples from Literature 2348.3.2 Examples Commercially Available 2398.4 Comparison of Different Types of RFID Temperature Sensors 2408.5 Conclusion 242References 2439 Autonomous System of Wireless Power Distribution for Static and Moving Nodes of Wireless Sensor Networks 247Przemyslaw Kant, Karol Dobrzyniewicz, and Jerzy Julian Michalski9.1 Introduction 2479.2 Data Routing in WSN Based on Multiple Spanning Trees Concept 2489.2.1 Multiple Spanning Trees Routing Protocol 2499.2.2 Software WSN Simulator 2529.2.3 Experimental Verification 2539.3 WPT System for 2D Distributed WSN 2569.3.1 System Concept 2579.3.2 Physical Realization of 2D WPT System 2609.3.3 Experimental Verification of the 2DWPT System 2649.3.4 Tests of 2D WPT System with Implemented Switching Algorithm 2669.4 WPT System for 3D Distributed WSN 2699.4.1 Design of Components of the 3D WPT System 2729.5 Locating System and Electromagnetic Power Supply for WSN in 3D Space 2759.5.1 Tracking Subsystem 2769.5.2 Data Exchange System 2789.5.3 Angular Position Estimation of Moving WSN Node 2799.5.4 Experimental Verification 2819.5.5 Adaptation of the System to WPT for WSN 2829.5.5.1 Tracking System 2829.5.5.2 WSN Node 2829.6 Summary 283References 28410 Smartphone Reception of Microwatt, Meter to Kilometer Range Backscatter Resistive/Capacitive Sensors with Ambient FM Remodulation and Selection Diversity 287Georgios Vougioukas and Aggelos Bletsas10.1 Introduction 28710.2 Operating Principle 29110.2.1 Backscatter Communication 29110.2.2 FM Remodulation 29210.3 Impact of Noise 29310.3.1 High SNR Case 29410.3.2 Low SNR Case 30110.4 Occupied Bandwidth 30210.5 Ambient Selection Diversity 30310.6 Analog Tag Implementation 30410.6.1 Sensing Capacitor and Control Circuit 30510.6.1.1 Generating 𝜇(t) – First Modulation Level 30510.6.1.2 Generating xFM(t) – Second Modulation Level 30610.6.2 RF-Switch 30610.6.3 Power Consumption and Supply 30610.6.3.1 Batteryless Tag with Photodiode 30710.6.3.2 Batteryless Tag with Solar Panel 30710.6.3.3 Batteryless Tag with Lemons 30710.6.4 Receiver 30810.6.4.1 Smartphone 30810.6.4.2 Computer 30910.7 Performance Characterization 30910.7.1 Simulation Results 30910.7.2 Tag Indoor and Outdoor Performance 31210.8 Conclusions 31310.9 Bandwidth of J0 (2𝜌 sin (𝜔sens/2 t)) 31410.10 Expectation of the Absolute Value of a Gaussian R.V 31610.11 Probability of Outage Under Ambient Selection Diversity 316Acknowledgment 318References 31811 Design of an ULP-ULV RF-Powered CMOS Front-End for Low-Rate Autonomous Sensors 323Hugo García-Vázquez, Alexandre Quenon, Grigory Popov, and Fortunato Carlos Dualibe11.1 Introduction 32311.2 Characterization of the Technology 32611.2.1 gm/ID Curves 32611.2.2 COX and μCOX 32911.2.3 Early Voltage (VA) 33111.3 Ultra-Low Power and Ultra-Low Voltage RF-Powered Transceiver for Autonomous Sensors 33211.3.1 Power Management (PM) and Receiver (RX) 33211.3.1.1 Rectifier 33311.3.1.2 Voltage Reference (VREF) Circuit 33511.3.1.3 Comparator for Power Management (COMP1) 33511.3.1.4 Current Reference Circuit (IREF) 33611.3.1.5 Comparator for the Demodulation (COMP2) 33611.3.2 Control Unit (CU) 33611.3.3 Transmitter (TX) 33711.3.3.1 Voltage-controlled oscillator (VCO) 33711.3.3.2 Power amplifier (PA) with built-in driver 34011.4 Experimental Results 34111.5 Conclusion 343Acknowledgments 343References 34412 Rectenna Optimization Guidelines for Ambient Electromagnetic Energy Harvesting 347Erika Vandelle, Simon Hemour, Tan-Phu Vuong, Gustavo Ardila, and Ke Wu12.1 Introduction 34712.2 Rectennas Under Low Input Powers 34812.2.1 Rectifier Optimization 35012.2.2 Low Power Matching Network Optimization 35312.2.2.1 The Bode-Fano Criterion 35312.2.2.2 Matching Network Efficiency 35412.2.3 Low-Power Antenna Optimization 35612.2.3.1 Enhancement of the Output DC Power 35712.2.3.2 Rectenna Array 35812.2.3.3 Antenna Array with BFN 35812.2.3.4 Optimization of the Antenna Efficiency 36112.3 The Chance of Collecting Ambient Electromagnetic Energy with a Specific Antenna 36112.3.1 Frequency Spectrum 36212.3.2 Polarization 36212.3.3 Spatial Coverage 36512.3.4 Harvesting Capability 36612.4 Conclusion 367References 368Index 375

NUNO BORGES CARVALHO, PHD, is a Full Professor at DETI, University of Aveiro, a Senior Research Scientist with the Institute of Telecommunications, and an IEEE Fellow. He is associate editor of the IEEE Microwave Magazine and Cambridge Wireless Power Transfer Journal and former associate editor of the IEEE Transactions on Microwave Theory and Techniques. Dr. Borges Carvalho belongs to the ADCOM of IEEE-MTT and is the Vice-Chair of the URSI Commission A (Metrology Group).APOSTOLOS GEORGIADIS, PHD, is Honorary Associate Professor at Heriot-Watt University, Edinburgh, UK. He is Vice-Chair of EU COST Action IC1301 on Wireless Power Transfer for Sustainable Electronics. He is former Editor-in-Chief of Cambridge Wireless Power Transfer Journal and former Associate Editor of the IEEE Microwave Wireless Components Letters and IET Microwaves Antennas and Propagation journals. He is Chairman of URSI Commission D Electronics and Photonics and a Distinguished Lecturer of IEEE Council on RFID (CRFID).

• List of Figures xiiiList of Contributors xxxiiiPreface xxxviiAcknowledgments xxxix1 Textile-Supported Wireless Energy Transfer 1Miroslav Cupal, Jaroslav Láčík, Zbynĕk Raida, Jan Špůrek, and Jan Vélim1.1 Introduction 11.2 Textile-Coated Single-Wire Transmission Line 31.3 Textile-Integrated Components 61.3.1 Fabrication of the Top Conductive Layer and the Bottom One 81.3.2 Fabrication of Conductive Vias of Side Walls 81.4 In-Vehicle Wireless Energy Transfer 151.5 Summary 24References 252 A Review of Methods for the Electromagnetic Characterization of Textile Materials for the Development of Wearable Antennas 27Caroline Loss, Ricardo Gonçalves, Pedro Pinho, and Rita Salvado2.1 Introduction 272.2 Electromagnetic Properties of Materials 292.2.1 Conductive Fabrics 292.2.2 Dielectric Fabrics 312.3 Dielectric Characterization Methods Applied to Textile Materials and Leather: A Survey 322.3.1 Resonant Methods 332.3.1.1 Cavity Perturbation Methods 332.3.1.2 Microstrip Resonator Patch Method 352.3.1.3 Microstrip Resonator Ring Method 352.3.1.4 Microstrip Patch Sensor 352.3.1.5 Agilent 85070E Dielectric Measurement Probe Kit 392.3.1.6 Summary of the Characterization of Textile Materials by Resonant Methods 402.3.2 Nonresonant Methods 402.3.2.1 Parallel Plate Method 402.3.2.2 Free Space Methods 412.3.2.3 Planar Transmission Lines Methods 442.3.2.4 Summary of the Characterization of Textile Materials by Nonresonant Methods 462.4 Some Factors that Affect the Measurement of Dielectric Properties of Textiles 462.4.1 Influence of the Moisture Content 462.4.2 Influence of the Material Anisotropy 472.4.3 Influence of the Bulk Porosity 472.4.4 Influence of the Surface Features 482.5 Conclusions 48Acknowledgments 50References 503 Smart Beamforming Techniques for “On Demand” WPT 57Diego Masotti, Mazen Shanawani, and Alessandra Costanzo3.1 Introduction 573.2 Basics of Time-modulated Arrays 613.3 Nonlinear/Full-Wave Co-simulation of TMAS 633.4 Two-Step Agile WPT Strategy 643.4.1 Localization Step 653.4.2 Power Transfer Step 663.5 Simulation Results 683.5.1 Localization Step 683.5.2 Power Transfer Step 693.6 Measured Results 733.7 TMA Architecture for Fundamental Pattern Steering 763.8 Conclusion 81References 824 Backscatter a Solution for IoT Devices 85Daniel Belo, Ricardo Correia, Marina Jordao, Pedro Pinho, and Nuno B. Carvalho4.1 Backscatter Basics 854.1.1 Different Backscatter Sensors Development 874.1.2 Backscatter with WPT Capabilities 874.1.3 High-Order Backscatter Modulation 884.1.4 Modulated High-Bandwidth Backscatter with WPT Capabilities 894.2 An IoT-Complete Sensor with Backscatter Capabilities 904.2.1 System Description 914.2.2 Digital Component 924.2.3 Measurements 944.3 The Power Availability for These Sensors 974.3.1 Electronically Steerable Phased Array for Wireless Power Transfer Applications 984.3.2 Wireless Energy Receiving Device 1014.3.3 Experimental Results 1044.4 Characterization of High-Order Modulation Backscatter Systems 1074.4.1 Characterization System 1074.4.2 Measurements 110References 1145 Ambient FM Backscattering Low-Cost and Low-Power Wireless RFID Applications 117Spyridon N. Daskalakis, Ricardo Correia, John Kimionis, George Goussetis, Manos M. Tentzeris, Nuno B. Carvalho, and Apostolos Georgiadis5.1 Introduction 1175.2 Ambient Backscattering 1205.2.1 Ambient FM Backscattering 1225.2.2 Binary Modulation Tag 1245.2.3 4-PAM Tag 1255.2.4 Binary Telecommunication Protocol 1275.2.5 4-PAM Telecommunication Protocol 1295.2.6 Receiver 1295.2.7 Software Binary Receiver 1305.2.8 Software 4-PAM Receiver 1325.2.9 Experimental and Measurement Results 1325.3 Conclusions 138Acknowledgments 139References 1396 Backscatter RFID Sensor System for Remote Health Monitoring 145Jasmin Grosinger6.1 Introduction 1456.2 On-Body System 1466.2.1 Body Model 1466.2.2 Antennas 1496.2.2.1 Monopole Antennas 1496.2.2.2 Patch Antennas 1516.3 Radio Channel 1526.3.1 Measurement Setup 1536.3.2 Comparison of Simulations and Measurements 1546.3.3 Measurement Results 1566.3.3.1 Antenna Matching 1566.3.3.2 Channel Gain 1576.4 System Performance 1596.4.1 Forward Link 1626.4.1.1 System Example 1656.4.2 Backward Link 1666.4.2.1 System Example 1666.5 Conclusions 168Acknowledgments 169References 1707 Robotics Meets RFID for Simultaneous Localization (of Robots and Objects) and Mapping (SLAM) – A Joined Problem 175Antonis G. Dimitriou, Stavroula Siachalou, Emmanouil Tsardoulias, and Loukas Petrou7.1 Scope 1757.2 Introduction 1767.3 Localization of RFID Tags – Prior Art 1827.3.1 Multipath in Passive RFID Systems 1847.3.2 Representative Localization Techniques 1857.3.2.1 Angle of Arrival 1857.3.2.2 Received Signal Strength – Bayes’ Theorem and Conditional Probability 1877.3.2.3 Fingerprinting – “Landmarc” 1897.3.2.4 Holographic Localization 1907.3.2.5 Other Methods 1927.3.3 Analysis of Prior Art 1947.4 A Brief Introduction in SLAM/Localization Techniques 1957.4.1 Introduction to Localization, Mapping, and SLAM 1967.4.2 Mathematical Formulation of SLAM 1977.4.3 Probabilistically Solving SLAM 1987.4.4 Space Representation in SLAM 2017.4.5 SLAM Algorithm Selection 2027.4.5.1 What are the Robot’s Sensors? 2027.4.5.2 Which is the Environmental Morphology? 2037.4.5.3 How Will the Generated Map Be Utilized? 2037.4.6 SLAM/Localization and RFID Localization Issues 2047.5 Prototype – Experimental Results 2067.5.1 Equipment 2067.5.2 Methodology 2087.5.2.1 Phase 1 2087.5.2.2 Phase 2 2097.5.3 Results 2127.6 Discussion 216Acknowledgments 218References 2188 From Identification to Sensing: Augmented RFID Tags 223Konstantinos Zannas, Hatem El Matbouly, Yvan Duroc, and Smail Tedjini8.1 Introduction 2238.2 Generic RFID Communication Chain 2268.2.1 RFID Sensor Tag 2268.2.2 RFID Data Capture Level 2288.2.3 RFID Tag Process Level 2298.2.4 RFID Communication Channel 2318.2.5 RFID Reader Process Level and RFID Reader 2328.3 RFID Sensor Tags: Examples from Literature or Commercially Available 2338.3.1 Examples from Literature 2348.3.2 Examples Commercially Available 2398.4 Comparison of Different Types of RFID Temperature Sensors 2408.5 Conclusion 242References 2439 Autonomous System of Wireless Power Distribution for Static and Moving Nodes of Wireless Sensor Networks 247Przemyslaw Kant, Karol Dobrzyniewicz, and Jerzy Julian Michalski9.1 Introduction 2479.2 Data Routing in WSN Based on Multiple Spanning Trees Concept 2489.2.1 Multiple Spanning Trees Routing Protocol 2499.2.2 Software WSN Simulator 2529.2.3 Experimental Verification 2539.3 WPT System for 2D Distributed WSN 2569.3.1 System Concept 2579.3.2 Physical Realization of 2D WPT System 2609.3.3 Experimental Verification of the 2DWPT System 2649.3.4 Tests of 2D WPT System with Implemented Switching Algorithm 2669.4 WPT System for 3D Distributed WSN 2699.4.1 Design of Components of the 3D WPT System 2729.5 Locating System and Electromagnetic Power Supply for WSN in 3D Space 2759.5.1 Tracking Subsystem 2769.5.2 Data Exchange System 2789.5.3 Angular Position Estimation of Moving WSN Node 2799.5.4 Experimental Verification 2819.5.5 Adaptation of the System to WPT for WSN 2829.5.5.1 Tracking System 2829.5.5.2 WSN Node 2829.6 Summary 283References 28410 Smartphone Reception of Microwatt, Meter to Kilometer Range Backscatter Resistive/Capacitive Sensors with Ambient FM Remodulation and Selection Diversity 287Georgios Vougioukas and Aggelos Bletsas10.1 Introduction 28710.2 Operating Principle 29110.2.1 Backscatter Communication 29110.2.2 FM Remodulation 29210.3 Impact of Noise 29310.3.1 High SNR Case 29410.3.2 Low SNR Case 30110.4 Occupied Bandwidth 30210.5 Ambient Selection Diversity 30310.6 Analog Tag Implementation 30410.6.1 Sensing Capacitor and Control Circuit 30510.6.1.1 Generating 𝜇(t) – First Modulation Level 30510.6.1.2 Generating xFM(t) – Second Modulation Level 30610.6.2 RF-Switch 30610.6.3 Power Consumption and Supply 30610.6.3.1 Batteryless Tag with Photodiode 30710.6.3.2 Batteryless Tag with Solar Panel 30710.6.3.3 Batteryless Tag with Lemons 30710.6.4 Receiver 30810.6.4.1 Smartphone 30810.6.4.2 Computer 30910.7 Performance Characterization 30910.7.1 Simulation Results 30910.7.2 Tag Indoor and Outdoor Performance 31210.8 Conclusions 31310.9 Bandwidth of J0 (2𝜌 sin (𝜔sens/2 t)) 31410.10 Expectation of the Absolute Value of a Gaussian R.V 31610.11 Probability of Outage Under Ambient Selection Diversity 316Acknowledgment 318References 31811 Design of an ULP-ULV RF-Powered CMOS Front-End for Low-Rate Autonomous Sensors 323Hugo García-Vázquez, Alexandre Quenon, Grigory Popov, and Fortunato Carlos Dualibe11.1 Introduction 32311.2 Characterization of the Technology 32611.2.1 gm/ID Curves 32611.2.2 COX and μCOX 32911.2.3 Early Voltage (VA) 33111.3 Ultra-Low Power and Ultra-Low Voltage RF-Powered Transceiver for Autonomous Sensors 33211.3.1 Power Management (PM) and Receiver (RX) 33211.3.1.1 Rectifier 33311.3.1.2 Voltage Reference (VREF) Circuit 33511.3.1.3 Comparator for Power Management (COMP1) 33511.3.1.4 Current Reference Circuit (IREF) 33611.3.1.5 Comparator for the Demodulation (COMP2) 33611.3.2 Control Unit (CU) 33611.3.3 Transmitter (TX) 33711.3.3.1 Voltage-controlled oscillator (VCO) 33711.3.3.2 Power amplifier (PA) with built-in driver 34011.4 Experimental Results 34111.5 Conclusion 343Acknowledgments 343References 34412 Rectenna Optimization Guidelines for Ambient Electromagnetic Energy Harvesting 347Erika Vandelle, Simon Hemour, Tan-Phu Vuong, Gustavo Ardila, and Ke Wu12.1 Introduction 34712.2 Rectennas Under Low Input Powers 34812.2.1 Rectifier Optimization 35012.2.2 Low Power Matching Network Optimization 35312.2.2.1 The Bode-Fano Criterion 35312.2.2.2 Matching Network Efficiency 35412.2.3 Low-Power Antenna Optimization 35612.2.3.1 Enhancement of the Output DC Power 35712.2.3.2 Rectenna Array 35812.2.3.3 Antenna Array with BFN 35812.2.3.4 Optimization of the Antenna Efficiency 36112.3 The Chance of Collecting Ambient Electromagnetic Energy with a Specific Antenna 36112.3.1 Frequency Spectrum 36212.3.2 Polarization 36212.3.3 Spatial Coverage 36512.3.4 Harvesting Capability 36612.4 Conclusion 367References 368Index 375

NUNO BORGES CARVALHO, PHD, is a Full Professor at DETI, University of Aveiro, a Senior Research Scientist with the Institute of Telecommunications, and an IEEE Fellow. He is associate editor of the IEEE Microwave Magazine and Cambridge Wireless Power Transfer Journal and former associate editor of the IEEE Transactions on Microwave Theory and Techniques. Dr. Borges Carvalho belongs to the ADCOM of IEEE-MTT and is the Vice-Chair of the URSI Commission A (Metrology Group).APOSTOLOS GEORGIADIS, PHD, is Honorary Associate Professor at Heriot-Watt University, Edinburgh, UK. He is Vice-Chair of EU COST Action IC1301 on Wireless Power Transfer for Sustainable Electronics. He is former Editor-in-Chief of Cambridge Wireless Power Transfer Journal and former Associate Editor of the IEEE Microwave Wireless Components Letters and IET Microwaves Antennas and Propagation journals. He is Chairman of URSI Commission D Electronics and Photonics and a Distinguished Lecturer of IEEE Council on RFID (CRFID).

• List of Figures xiiiList of Contributors xxxiiiPreface xxxviiAcknowledgments xxxix1 Textile-Supported Wireless Energy Transfer 1Miroslav Cupal, Jaroslav Láčík, Zbynĕk Raida, Jan Špůrek, and Jan Vélim1.1 Introduction 11.2 Textile-Coated Single-Wire Transmission Line 31.3 Textile-Integrated Components 61.3.1 Fabrication of the Top Conductive Layer and the Bottom One 81.3.2 Fabrication of Conductive Vias of Side Walls 81.4 In-Vehicle Wireless Energy Transfer 151.5 Summary 24References 252 A Review of Methods for the Electromagnetic Characterization of Textile Materials for the Development of Wearable Antennas 27Caroline Loss, Ricardo Gonçalves, Pedro Pinho, and Rita Salvado2.1 Introduction 272.2 Electromagnetic Properties of Materials 292.2.1 Conductive Fabrics 292.2.2 Dielectric Fabrics 312.3 Dielectric Characterization Methods Applied to Textile Materials and Leather: A Survey 322.3.1 Resonant Methods 332.3.1.1 Cavity Perturbation Methods 332.3.1.2 Microstrip Resonator Patch Method 352.3.1.3 Microstrip Resonator Ring Method 352.3.1.4 Microstrip Patch Sensor 352.3.1.5 Agilent 85070E Dielectric Measurement Probe Kit 392.3.1.6 Summary of the Characterization of Textile Materials by Resonant Methods 402.3.2 Nonresonant Methods 402.3.2.1 Parallel Plate Method 402.3.2.2 Free Space Methods 412.3.2.3 Planar Transmission Lines Methods 442.3.2.4 Summary of the Characterization of Textile Materials by Nonresonant Methods 462.4 Some Factors that Affect the Measurement of Dielectric Properties of Textiles 462.4.1 Influence of the Moisture Content 462.4.2 Influence of the Material Anisotropy 472.4.3 Influence of the Bulk Porosity 472.4.4 Influence of the Surface Features 482.5 Conclusions 48Acknowledgments 50References 503 Smart Beamforming Techniques for “On Demand” WPT 57Diego Masotti, Mazen Shanawani, and Alessandra Costanzo3.1 Introduction 573.2 Basics of Time-modulated Arrays 613.3 Nonlinear/Full-Wave Co-simulation of TMAS 633.4 Two-Step Agile WPT Strategy 643.4.1 Localization Step 653.4.2 Power Transfer Step 663.5 Simulation Results 683.5.1 Localization Step 683.5.2 Power Transfer Step 693.6 Measured Results 733.7 TMA Architecture for Fundamental Pattern Steering 763.8 Conclusion 81References 824 Backscatter a Solution for IoT Devices 85Daniel Belo, Ricardo Correia, Marina Jordao, Pedro Pinho, and Nuno B. Carvalho4.1 Backscatter Basics 854.1.1 Different Backscatter Sensors Development 874.1.2 Backscatter with WPT Capabilities 874.1.3 High-Order Backscatter Modulation 884.1.4 Modulated High-Bandwidth Backscatter with WPT Capabilities 894.2 An IoT-Complete Sensor with Backscatter Capabilities 904.2.1 System Description 914.2.2 Digital Component 924.2.3 Measurements 944.3 The Power Availability for These Sensors 974.3.1 Electronically Steerable Phased Array for Wireless Power Transfer Applications 984.3.2 Wireless Energy Receiving Device 1014.3.3 Experimental Results 1044.4 Characterization of High-Order Modulation Backscatter Systems 1074.4.1 Characterization System 1074.4.2 Measurements 110References 1145 Ambient FM Backscattering Low-Cost and Low-Power Wireless RFID Applications 117Spyridon N. Daskalakis, Ricardo Correia, John Kimionis, George Goussetis, Manos M. Tentzeris, Nuno B. Carvalho, and Apostolos Georgiadis5.1 Introduction 1175.2 Ambient Backscattering 1205.2.1 Ambient FM Backscattering 1225.2.2 Binary Modulation Tag 1245.2.3 4-PAM Tag 1255.2.4 Binary Telecommunication Protocol 1275.2.5 4-PAM Telecommunication Protocol 1295.2.6 Receiver 1295.2.7 Software Binary Receiver 1305.2.8 Software 4-PAM Receiver 1325.2.9 Experimental and Measurement Results 1325.3 Conclusions 138Acknowledgments 139References 1396 Backscatter RFID Sensor System for Remote Health Monitoring 145Jasmin Grosinger6.1 Introduction 1456.2 On-Body System 1466.2.1 Body Model 1466.2.2 Antennas 1496.2.2.1 Monopole Antennas 1496.2.2.2 Patch Antennas 1516.3 Radio Channel 1526.3.1 Measurement Setup 1536.3.2 Comparison of Simulations and Measurements 1546.3.3 Measurement Results 1566.3.3.1 Antenna Matching 1566.3.3.2 Channel Gain 1576.4 System Performance 1596.4.1 Forward Link 1626.4.1.1 System Example 1656.4.2 Backward Link 1666.4.2.1 System Example 1666.5 Conclusions 168Acknowledgments 169References 1707 Robotics Meets RFID for Simultaneous Localization (of Robots and Objects) and Mapping (SLAM) – A Joined Problem 175Antonis G. Dimitriou, Stavroula Siachalou, Emmanouil Tsardoulias, and Loukas Petrou7.1 Scope 1757.2 Introduction 1767.3 Localization of RFID Tags – Prior Art 1827.3.1 Multipath in Passive RFID Systems 1847.3.2 Representative Localization Techniques 1857.3.2.1 Angle of Arrival 1857.3.2.2 Received Signal Strength – Bayes’ Theorem and Conditional Probability 1877.3.2.3 Fingerprinting – “Landmarc” 1897.3.2.4 Holographic Localization 1907.3.2.5 Other Methods 1927.3.3 Analysis of Prior Art 1947.4 A Brief Introduction in SLAM/Localization Techniques 1957.4.1 Introduction to Localization, Mapping, and SLAM 1967.4.2 Mathematical Formulation of SLAM 1977.4.3 Probabilistically Solving SLAM 1987.4.4 Space Representation in SLAM 2017.4.5 SLAM Algorithm Selection 2027.4.5.1 What are the Robot’s Sensors? 2027.4.5.2 Which is the Environmental Morphology? 2037.4.5.3 How Will the Generated Map Be Utilized? 2037.4.6 SLAM/Localization and RFID Localization Issues 2047.5 Prototype – Experimental Results 2067.5.1 Equipment 2067.5.2 Methodology 2087.5.2.1 Phase 1 2087.5.2.2 Phase 2 2097.5.3 Results 2127.6 Discussion 216Acknowledgments 218References 2188 From Identification to Sensing: Augmented RFID Tags 223Konstantinos Zannas, Hatem El Matbouly, Yvan Duroc, and Smail Tedjini8.1 Introduction 2238.2 Generic RFID Communication Chain 2268.2.1 RFID Sensor Tag 2268.2.2 RFID Data Capture Level 2288.2.3 RFID Tag Process Level 2298.2.4 RFID Communication Channel 2318.2.5 RFID Reader Process Level and RFID Reader 2328.3 RFID Sensor Tags: Examples from Literature or Commercially Available 2338.3.1 Examples from Literature 2348.3.2 Examples Commercially Available 2398.4 Comparison of Different Types of RFID Temperature Sensors 2408.5 Conclusion 242References 2439 Autonomous System of Wireless Power Distribution for Static and Moving Nodes of Wireless Sensor Networks 247Przemyslaw Kant, Karol Dobrzyniewicz, and Jerzy Julian Michalski9.1 Introduction 2479.2 Data Routing in WSN Based on Multiple Spanning Trees Concept 2489.2.1 Multiple Spanning Trees Routing Protocol 2499.2.2 Software WSN Simulator 2529.2.3 Experimental Verification 2539.3 WPT System for 2D Distributed WSN 2569.3.1 System Concept 2579.3.2 Physical Realization of 2D WPT System 2609.3.3 Experimental Verification of the 2DWPT System 2649.3.4 Tests of 2D WPT System with Implemented Switching Algorithm 2669.4 WPT System for 3D Distributed WSN 2699.4.1 Design of Components of the 3D WPT System 2729.5 Locating System and Electromagnetic Power Supply for WSN in 3D Space 2759.5.1 Tracking Subsystem 2769.5.2 Data Exchange System 2789.5.3 Angular Position Estimation of Moving WSN Node 2799.5.4 Experimental Verification 2819.5.5 Adaptation of the System to WPT for WSN 2829.5.5.1 Tracking System 2829.5.5.2 WSN Node 2829.6 Summary 283References 28410 Smartphone Reception of Microwatt, Meter to Kilometer Range Backscatter Resistive/Capacitive Sensors with Ambient FM Remodulation and Selection Diversity 287Georgios Vougioukas and Aggelos Bletsas10.1 Introduction 28710.2 Operating Principle 29110.2.1 Backscatter Communication 29110.2.2 FM Remodulation 29210.3 Impact of Noise 29310.3.1 High SNR Case 29410.3.2 Low SNR Case 30110.4 Occupied Bandwidth 30210.5 Ambient Selection Diversity 30310.6 Analog Tag Implementation 30410.6.1 Sensing Capacitor and Control Circuit 30510.6.1.1 Generating 𝜇(t) – First Modulation Level 30510.6.1.2 Generating xFM(t) – Second Modulation Level 30610.6.2 RF-Switch 30610.6.3 Power Consumption and Supply 30610.6.3.1 Batteryless Tag with Photodiode 30710.6.3.2 Batteryless Tag with Solar Panel 30710.6.3.3 Batteryless Tag with Lemons 30710.6.4 Receiver 30810.6.4.1 Smartphone 30810.6.4.2 Computer 30910.7 Performance Characterization 30910.7.1 Simulation Results 30910.7.2 Tag Indoor and Outdoor Performance 31210.8 Conclusions 31310.9 Bandwidth of J0 (2𝜌 sin (𝜔sens/2 t)) 31410.10 Expectation of the Absolute Value of a Gaussian R.V 31610.11 Probability of Outage Under Ambient Selection Diversity 316Acknowledgment 318References 31811 Design of an ULP-ULV RF-Powered CMOS Front-End for Low-Rate Autonomous Sensors 323Hugo García-Vázquez, Alexandre Quenon, Grigory Popov, and Fortunato Carlos Dualibe11.1 Introduction 32311.2 Characterization of the Technology 32611.2.1 gm/ID Curves 32611.2.2 COX and μCOX 32911.2.3 Early Voltage (VA) 33111.3 Ultra-Low Power and Ultra-Low Voltage RF-Powered Transceiver for Autonomous Sensors 33211.3.1 Power Management (PM) and Receiver (RX) 33211.3.1.1 Rectifier 33311.3.1.2 Voltage Reference (VREF) Circuit 33511.3.1.3 Comparator for Power Management (COMP1) 33511.3.1.4 Current Reference Circuit (IREF) 33611.3.1.5 Comparator for the Demodulation (COMP2) 33611.3.2 Control Unit (CU) 33611.3.3 Transmitter (TX) 33711.3.3.1 Voltage-controlled oscillator (VCO) 33711.3.3.2 Power amplifier (PA) with built-in driver 34011.4 Experimental Results 34111.5 Conclusion 343Acknowledgments 343References 34412 Rectenna Optimization Guidelines for Ambient Electromagnetic Energy Harvesting 347Erika Vandelle, Simon Hemour, Tan-Phu Vuong, Gustavo Ardila, and Ke Wu12.1 Introduction 34712.2 Rectennas Under Low Input Powers 34812.2.1 Rectifier Optimization 35012.2.2 Low Power Matching Network Optimization 35312.2.2.1 The Bode-Fano Criterion 35312.2.2.2 Matching Network Efficiency 35412.2.3 Low-Power Antenna Optimization 35612.2.3.1 Enhancement of the Output DC Power 35712.2.3.2 Rectenna Array 35812.2.3.3 Antenna Array with BFN 35812.2.3.4 Optimization of the Antenna Efficiency 36112.3 The Chance of Collecting Ambient Electromagnetic Energy with a Specific Antenna 36112.3.1 Frequency Spectrum 36212.3.2 Polarization 36212.3.3 Spatial Coverage 36512.3.4 Harvesting Capability 36612.4 Conclusion 367References 368Index 375