Wireless Power Transmission for Sustainable Electronics

COST WiPE - IC1301

Nuno Borges Carvalho, Apostolos Georgiadis, Nuno Borges Carvalho, Apostolos Georgiadis

• Publisher: Wiley
• Year: 2020
• Print ISBN: 9781119578543
• eBook ISBN: 9781119578574
• Edition: 1
• Topic: Technology & Engineering
• Subtopic: Power Resources
• Index: Technology & Engineering

Provides a collection of works produced by COST Action IC1301 with the goal of achieving significant advances in the field of wireless power transmission

This bookconstitutes together information from COST Action IC1301, a group of academic and industry experts seeking to align research efforts in the field of wireless power transmission (WPT). It begins with a discussion of backscatter as a solution for Internet of Things (IoT) devices and goes on to describe ambient backscattering sensors that use FM broadcasting for low cost and low power wireless applications. The book also explores localization of passive RFID tags and augmented tags using nonlinearities of RFID chips. It concludes with a review of methods of electromagnetic characterization of textile materials for the development of wearable antennas.

Wireless Power Transmission for Sustainable Electronics: COST WiPE - IC1301 covers textile-supported wireless energy transfer, and reviews methods for the electromagnetic characterization of textile materials for the development of wearable antennas. It also looks at: backscatter RFID sensor systems for remote health monitoring; simultaneous localization (of robots and objects) and mapping (SLAM); autonomous system of wireless power distribution for static and moving nodes of wireless sensor networks; and more.

• Presents techniques for smart beam-forming for "on demand" wireless power transmission (WPT)
• Discusses RF and microwave energy harvesting for space applications
• Describes miniaturized RFID transponders for object identification and sensing

Wireless Power Transmission for Sustainable Electronics: COST WiPE - IC1301 is an excellent book for both graduate students and industry engineers involved in wireless communications and power transfer, and sustainable materials for those fields.

1
Textile‐Supported Wireless Energy Transfer

Miroslav Cupal, Jaroslav Láčík, Zbyněk Raida, Jan Špůrek, and Jan Vélim

Department of Radio Electronics, Faculty of Electrical Engineering and Communication, Brno University of Technology, Brno, Czech Republic

1.1 Introduction

In daily use, wired technologies are extensively replaced by wireless ones. Whereas wireless communication has been reaching its maturity, wireless energy transfer has been still developing.

Using a conventional coaxial cable for transmitting electromagnetic energy, attenuation about 6 dB can be reached at f = 2 GHz for the distance R = 100 m [1]. If the energy is transmitted at the same frequency for the same distance in free space using two half‐wavelength dipoles, attenuation can be evaluated by Friis equation [2]

(1.1)

where c is velocity of light and G₁ = G₂ = 1.64 is gain of a half‐wavelength dipole. Substituting numerical values to (1.1), we obtain the corresponding attenuation 75 dB if no losses and perfect matching are assumed.

The presented simplified calculation shows that low efficiency is the main disadvantage of a far‐field wireless energy transfer:

• In wired transmission, a plane wave is propagating with constant amplitude in a single direction (along a transmission line). Attenuation is therefore mainly caused by losses in metallic conductors and dielectrics.
• In wireless transmission, antennas radiate a spherical wave, which intensity is reciprocally proportional to the distance, to all directions in space. Attenuation caused by losses can be usually neglected.
• Whereas reciprocal proportion between the field intensity and the distance cannot be influenced, energy propagation can be limited to a selected subspace, and efficiency of the wireless energy transfer can be improved that way. If a half‐wavelength dipole is replaced by a quarter‐wavelength monopole (Figure 1.1), only the half‐space above the reflector is filled‐in by energy (radiation resistance of the antenna is half‐sized), and transmission can be improved for +3 dB.

Figure 1.1 On‐surface wireless energy transfer: replacing dipole antenna by monopole one.

Let us assume a perfectly electrically conductive (PEC) reflector being coated by a layer of dielectrics. Then, this coated structure can play the role of a single‐wire transmission line [3]:

• — The conductive shield of a coaxial line is projected into the plane;
• — The inner dielectric insulator is projected into the coating;
• — The conductive core is going to vanish.

Since the single‐wire transmission line is an open structure, wave propagation stays attenuated due to radiation losses. On the other hand, resistive and dielectric losses are much smaller than in closed structures because the field is not confined to a small area [3].

So, the single‐layer transmission line seems to be a good candidate for wireless energy transfer along coated conductive surfaces. Since bodies of cars, buses, and airplanes are conductive, such an energy transfer can be used for energy distribution along the surface of vehicles.

In Section 1.2, we investigate exploitation of a three‐dimensional (3D) knitted fabric for coating of conductive surfaces. Next to creating the single‐wire transmission line, the knitted coating can provide additional functions. The knitted coating can:

• — Play the role of a microwave substrate for manufacturing transmission lines, antennas, and electronic circuits.
• — Be used for thermal insulation of vehicle interior.
• — Attenuate vibrations and other mechanical phenomena.
• — Provide functional properties of textile components (covers of seats, textile upholstery, etc.).

Integration of several functions into a knitted coating is the main idea of so called intelligent fabrics. Such fabrics can obviously reduce fabrication costs, weight of vehicle, and consequently, fuel consumption, and CO₂ emissions. Examples of integrated components and subsystems are described in Section 1.3.

A conductive surface of a vehicle covered by intelligent fabrics can play the role of the distribution network for an in‐vehicle wireless communication (or wireless energy transfer). Antennas integrated into the fabrics can be understood as an interface in between this network and interior of the vehicle. Wireless communication between the on‐surface network and interior of a vehicle is discussed i...

Table of contents

• Cover
• Table of Contents
• List of Figures
• List of Contributors
• Preface
• Acknowledgments
• 1 Textile‐Supported Wireless Energy Transfer
• 2 A Review of Methods for the Electromagnetic Characterization of Textile Materials for the Development of Wearable Antennas
• 3 Smart Beamforming Techniques for “On Demand” WPT
• 4 Backscatter a Solution for IoT Devices
• 5 Ambient FM Backscattering Low‐Cost and Low‐Power Wireless RFID Applications
• 6 Backscatter RFID Sensor System for Remote Health Monitoring
• 7 Robotics Meets RFID for Simultaneous Localization (of Robots and Objects) and Mapping (SLAM) – A Joined Problem
• 8 From Identification to Sensing: Augmented RFID Tags
• 9 Autonomous System of Wireless Power Distribution for Static and Moving Nodes of Wireless Sensor Networks
• 10 Smartphone Reception of Microwatt, Meter to Kilometer Range Backscatter Resistive/Capacitive Sensors with Ambient FM Remodulation and Selection Diversity
• 11 Design of an ULP‐ULV RF‐Powered CMOS Front‐End for Low‐Rate Autonomous Sensors
• 12 Rectenna Optimization Guidelines for Ambient Electromagnetic Energy Harvesting
• Index
• End User License Agreement