Wireless Identification and Sensing Systems for Harsh and Severe Environments E-Book

• Herausgeber: John Wiley & Sons
• Kategorie: Wissenschaft und neue Technologien
• Sprache: Englisch

Seitenzahl: 640

Veröffentlichungsjahr: 2025

Beschreibung

Comprehensive resource reviewing the state of the artin wireless identification and sensing systems, proposing several examples of applications

While complying with RF standard and regulations, Wireless Identification and Sensing Systems for Harsh and Severe Environments covers the recent advances in wireless and radio-frequency identification (RFID) systems where severe electromagnetic behavior and harsh conditions are taken into consideration, providing the reader with design rules and methodologies to obtain satisfactory performance and avoid the typical oversights and mistakes that can be made when first approaching this topic.

In addition to examples of real implementations, the book gives a general overview of RFID and wireless technologies as well as their pros and cons in terms of expected performance and future directions of technologies. The perspective and evolution towards IoT solutions and artificial intelligence (AI) are pointed out.

The book furthermore addresses chipless RFID frameworks from the theoretical perspective as well as that of implementation, including examples from scientific literature and commercial solutions. It also describes surface acoustic wave (SAW) sensors in wired and wireless configurations and developments needed to implement the technology.

Wireless Identification and Sensing Systems for Harsh and Severe Environments includes discussion of:

• Frequency diversity for robust Ultra-High Frequency (UHF)-RFID communication, a key technology for future sensor and actuator devices in the Internet of Things, and harmonic transponders for tracking and sensing
• Resonator and reflective delay line configurations, and chipless RFID technology for operations in harsh environments
• Potential of battery-less near-field communication (NFC) sensors using mobile phones as readers in severe environments
• Chipless RFID channel modeling, considering the spatial multipath channel, 3D bi-static Radar Cross Section (RCS) tag model, and analogue effects

Providing comprehensive coverage of the subject and examples of successful implementations of wireless solutions exploiting RFID technologies and enabling systems for the Internet of Things (IoT), Wireless Identification and Sensing Systems for Harsh and Severe Environments is an essential resource for engineers and PhD students in wireless and RFID technologies.

Leseprobe

IEEE Press445 Hoes LanePiscataway, NJ 08854

IEEE Press Editorial BoardSarah Spurgeon, Editor‐in‐Chief

Moeness Amin

Ekram Hossain

Desineni Subbaram Naidu

Jón Atli Benediktsson

Brian Johnson

Tony Q. S. Quek

Adam Drobot

Hai Li

Behzad Razavi

James Duncan

James Lyke

Thomas Robertazzi

Joydeep Mitra

Diomidis Spinellis

Wireless Identification and Sensing Systems for Harsh and Severe Environments

Edited by

Smail Tedjini

Grenoble INP/LCISUniversity Grenoble AlpesValenceFrance

Valentina Palazzi

Department of EngineeringUniversity of PerugiaPerugiaItaly

Copyright © 2025 by The Institute of Electrical and Electronics Engineers, Inc. All rights reserved.

Published by John Wiley & Sons, Inc., Hoboken, New Jersey.Published simultaneously in Canada.

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.

Trademarks: Wiley and the Wiley logo are trademarks or registered trademarks of John Wiley & Sons, Inc. and/or its affiliates in the United States and other countries and may not be used without written permission. All other trademarks are the property of their respective owners. John Wiley & Sons, Inc. is not associated with any product or vendor mentioned in this book.

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. Further, readers should be aware that websites listed in this work may have changed or disappeared between when this work was written and when it is read. Neither the publisher nor authors shall be liable for any loss of profit or any other commercial damages, including but not limited to 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.

Library of Congress Cataloging‐in‐Publication Data is applied for

Hardback ISBN 9781394169078

Cover Design: WileyCover Images: © Longhua Liao/Getty Images, © Weiquan Lin/Getty Images

To our families and to all the colleagues and mentors who inspired our research.

Foreword

When Smail and Valentina contacted me, asking to write a foreword for a new book which they were putting together as co-editors, I was thrilled. I have known Smail for nearly 20 years: first, through his pioneering publications on radio frequency identification (RFID), the field in which we both started working around the same time and then we finally met in person at one of the IEEE Antennas and Propagation Symposiums in the USA and kept in touch ever since. As for Valentina, I have known her publications on chipless and harmonic tags for years and finally had the pleasure to meet her in person last year in Valence, France. Both Smail and Valentina are world-class researchers, and they managed to put together a team of other high-caliber researchers in RFID, who wrote individual chapters for this great book.

RFID is a wireless technology that has been around for a while and significantly evolved. It now extends beyond pure identification (originally it was conceived as sort of a wireless barcode) and encompasses low-power wireless devices and systems with various sensing, networking, security, and localization capabilities. Hence, the generic term “RFID” is often used loosely to denote a variety of active and passive RF technologies: actively transmitting or passively backscattering, with energy-harvesting or battery-powered tags, etc. The focus of this particular book is passive RFID and its operation in severe environments.

While many active RF or wireless technologies can be used for sensing and communication, passive RFID is especially attractive and presents a very compelling low-cost, reliable, and scalable alternative to solutions based on various active wireless protocols. It is well positioned as a core technology for enhancing everyday physical objects with sensors and communication abilities and connecting them to the Internet of Things (IoT). Passive RFID deployments are growing in size and number as they help to solve numerous business use cases across various industries and supply chains. An estimated 40 billion passive RFID tags (also called transponders) have been sold in 2023 to a wide range of industries and businesses including consumer goods tracking, apparel tagging, security, access, healthcare, construction, airlines, etc., with a majority of that volume being RAIN and NFC tags.

Passive RFID can be classified into chipless and chip-based. Chipless RFID encompasses pure chipless tags (composed of multiple RF resonators), surface acoustic wave (SAW) tags (which may include a special non-semiconductor SAW chip), and harmonic tags (diodes are the only semiconductor devices used in those). Chip-based RFID tags use complex semiconductor ICs, containing more transistors than microprocessors used in PCs in mid-80’s. Passive RFID can work in various frequency bands such as LF (low frequency), HF (high frequency, also known as NFC), UHF (ultra high frequency, also known as RAIN), or microwave. Chip-based and chipless tags of different kinds described above have varying degrees of sophistication, and their design is often a tradeoff between functionality and cost. All passive RFID systems may be deployed in both far-field and near-field scenarios.

Basic RFID principles are well known by now, but many challenges lie in the practical implementation. This is exactly the area that this book targets: how various passive RFID systems (chip-based and chipless) work in real environments: in the presence of metal objects and moisture, in propagation environments that are not governed by Friis free-space equation, in applications where tags can be implanted in a human body or placed on food items, in situations where extreme radiation may occur, etc. The collection of chapters in this book represents a sampling of various active research topics in the field of passive RFID implementation in real environments, covering all of those cases above.

I am very excited to see this book in print and can’t wait to see what you, dear reader, will think about it. You opened this book because you are interested in RFID. I envy you, because I have already read it, and you still have this experience ahead of you. RFID technology will continue to develop and pose many interesting challenges for researchers and engineers in both academia and industry, such as yourself. I hope that this book will inspire you and will lead you to some new ideas. Who knows, maybe you will become a contributor to the next book on RFID.

Pavel NikitinSeattle, WAMay 2024

List of Contributors

Sara AmendolaRADIO6ENSE S.r.L.RomaItaly

Thierry AubertUniversité de Lorraine, CNRS, IJLNancyFrance

Rahul BhattacharyyaAuto‐ID Labs, Massachusetts Instituteof TechnologyBoston, MAUSA

Francesca BenassiDEI “Guglielmo Marconi”University of BolognaBolognaItaly

Martí BoadaDepartment of Electronic, Electricand Automatic EngineeringUniversitat Rovira i VirgiliTarragonaSpain

Michele BorgeseResearch and DevelopmentDepartment, SIAE MicroelettronicaMilanItaly

Mathieu Le BretonGéolithe CompanyCrollesFrance

ISTerre, Université Grenoble AlpesGrenobleFrance

Mathieu CasselENS, Université de LyonLyonFrance

Fanny CoffigniezInstitut d’Électronique et desSystèmes, Univ MontpellierMontpellierFrance

Filippo CostaDipartimento Ingegneriadell’Informazione, Università di PisaPisaItaly

Alessandra CostanzoDEI “Guglielmo Marconi”University of BolognaBolognaItaly

Francesco Alessio DicandiaIstituto di Elettronica e diIngegneria dell’Informazione edelle Telecomunicazioni, ConsiglioNazionale delle Ricerche (CNR)TorinoItaly

Yvan DurocUniv Lyon, Université ClaudeBernard Lyon 1, INSA Lyon, EcoleCentrale de Lyon, CNRSVilleurbanneFrance

Omar ElmazriaUniversité de Lorraine, CNRS, IJLNancyFrance

Cécile FloerUniversité de Lorraine, CNRS, IJLNancyFrance

Simone GenovesiDipartimento Ingegneriadell’Informazione, Università di PisaPisaItaly

David GirbauDepartment of Electronic, Electricand Automatic EngineeringUniversitat Rovira i VirgiliTarragonaSpain

Jasmin GrosingerInstitute of Microwave and PhotonicEngineering, Graz University ofTechnologyGrazAustria

Sami Hage‐AliUniversité de Lorraine, CNRS, IJLNancyFrance

Amirhossein Karami‐HorestaniCIMITEC, Departament d’EnginyeriaElectrònica, Universitat Autònomade BarcelonaBellaterraSpain

Antonio LázaroDepartment of Electronic, Electricand Automatic EngineeringUniversitat Rovira i VirgiliTarragonaSpain

Giuliano ManaraDipartimento Ingegneriadell’Informazione, Università di PisaItaly

Gaetano MarroccoTor Vergata University of Roma andRADIO6ENSE S.r.L.RomaItaly

Ferran MartínCIMITEC, Departament d’EnginyeriaElectrònica, Universitat Autònomade BarcelonaBellaterraSpain

Diego MasottiDEI “Guglielmo Marconi”University of BolognaBolognaItaly

Alicja Michalowska‐ForsythInstitute of Electronics, GrazUniversity of TechnologyGrazAustria

Carolina MiozziRADIO6ENSE S.r.L.RomaItaly

Manuel MonederoNXP Semiconductors GmbHMunichGermany

Cecilia OcchiuzziTor Vergata University of Roma andRADIO6ENSE S.r.L.RomaItaly

Giacomo PaoliniDEI “Guglielmo Marconi”, Universityof BolognaBolognaItaly

Valentina PalazziDepartment of EngineeringUniversity of PerugiaPerugiaItaly

Ferran ParedesCIMITEC, Departament d’EnginyeriaElectrònica, Universitat Autònomade BarcelonaBellaterraSpain

Camille RamadeTageosMontpellierFrance

Benjamin SagginIES, Univ Montpellier, CNRSMontpellierFrance

Brice SorliIES, Univ Montpellier, CNRSMontpellierFrance

Robert StarajUniversité Côte d’Azur, LEATLaboratoire Electronique Antenneset TélécommunicationsSophia AntipolisFrance

Smail TedjiniLCIS, University of Grenoble‐Alpes50 Rue Barthelemy de LaffemasValenceFrance

Philippe Le ThucUniversité Côte d’Azur, LEATLaboratoire Electronique Antenneset TélécommunicationsSophia AntipolisFrance

Arnaud VenaIES, Univ Montpellier, CNRSMontpellierFrance

Ramón VillarinoDepartment of Electronic, Electricand Automatic EngineeringUniversitat Rovira i VirgiliTarragonaSpain

Konstantinos ZannasLCIS, University of Grenoble‐Alpes50 Rue Barthelemy de LaffemasValenceFrance

About the Editors

Smail Tedjini, Life Fellow IEEE, URSI Fellow; Doctor d’Etat in Physics 1985 Grenoble University; senior researcher of CNRS 1986–1993; University full professor since 1993, now with Grenoble Institute of Technology. His main topics for both research and teaching, concern Applied Electromagnetism, RF, Optoelectronics, RFID, and Wireless Systems. He served as coordinator and staff member in numerous academic programs both for education and research. He was coordinator for PhD program, master and bachelor programs for the Universities at Grenoble, some of these programs are under collaboration with international universities from Europe, Canada, Brazil, Vietnam, Egypt, and Maghreb. He served as the director of Esisar, Department of Grenoble‐INP. He is involved in academic research supervision since 1982. His main topics in research are applied electromagnetism, modeling of devices and circuits at both RF and optoelectronic domains. Current research focuses on wireless systems with special attention to RFID technology and its applications. He is the founder in 1996 and past director of the LCIS Lab. Now, he is within ORSYS group that he leaded until 2014 and founded in 2002. He supervised tens of research contracts with public administrations and industries. He supervised 50 PhD, co‐authored 350 publications, 3 books, 7 patents, 10 book chapters, and book: Wiley “Non‐linearities in Passive RFID Systems” and served as reviewer/opponent for tens of PhD worldwide.

TPC‐Cochair of IEEE‐RFID2011 TPC Member for several editions of IEEE‐RFID, TPC member or cochair for RFID‐TA since 2010. General Chair IEEE RFID‐TA 2012. Organizer of IEEE‐RFID‐TA 2012 in France. Organizer/co‐organizer of RFID special sessions in numerous conferences in particular: IEEE‐MTTs, IEEE‐APs, IEEE‐RFID‐TA, EuMW, EuCAP, URSI‐GASS, URSI‐ATRASC, local conferences in France, Brazil, Vietnam, Tunisia. Organizer of RFID summer school in France, Brazil, Vietnam, and Maghreb. Organizer of (3) Student Design Competitions at IEEE‐IMS. Editor of special issue on RFID at IEEE‐microwave magazine, and Annales des telecom. Vice‐chair IEEE MTT‐TC 24 (2017–2019). Chair IEEE MTT‐TC‐26 (2020–2021), since 2024 he is the chair of French Chapter of IEEE‐Antenna and Propagation. Since October 2022 he is nominated as Emeritus professor at University Grenoble Alpes. Since 2024 he is Distinguish Lecturer of the IEEE Council on RFID.

Valentina Palazzi received the MS degree in electrical engineering and the PhD degree in industrial and information engineering from the University of Perugia, Italy, in 2014 and 2018, respectively. During her PhD, she was visiting PhD student at the Tyndall National Institute, Cork, Ireland, at the Centre Tecnològic de Telecomunicacions de Catalunya, Barcelona, Spain, and at the Georgia Institute of Technology, Atlanta, GA, USA. Currently, she is a researcher with the High Frequency Electronics Laboratory at the University of Perugia, Perugia, Italy. She has been the scientific coordinator for the University of Perugia of the European projects CHARM ‐ Challenging environments tolerant Smart systems for IoT and AI (G.A. n. 876362) and OPEVA ‐ Optimization of Electric Vehicle autonomy (G.A. n. 101097267).

She wrote more than 80 scientific papers (both journal and conference proceedings), and a book chapter, and she holds three patents. Her current research interests include the design of RF components, wireless sensors, radar front ends, wireless power transfer technologies, additive manufacturing, and conformal electronics.

Dr. Palazzi is an elected member of the IEEE Microwave Theory and Technology Society (MTT‐S) Administrative Committee from 2024 to 2026. She is a member of IEEE MTT‐S Technical Committees 16 “Microwave and Millimeter Wave Packaging Interconnect and Integration,” 17 “Microwave Materials and Processing Technologies,” and 26 “RFID, Wireless Sensor and IoT.” She was the Chair of the Technical Committee 26 from 2022 to 2023. She has been an Early Career Representative of the URSI Commission D “Electronics and Photonics” of the International Union of Radio Science (URSI) from 2021 to 2026. She won a number of international prizes, including the IEEE Graduate Fellowship in 2017, 2017 MTT‐S Prize–Italy Chapter Central and Southern Italy, and the International Union of Radio Science (URSI) Young Scientist Best Paper Award conferred at the 2019 URSI Italian National Meeting.

Since November 2024, she has served as an Associate Editor for IEEE Microwave and Wireless Technology Letters.

Preface

In the continuously evolving digital landscape, wireless systems are experiencing considerable developments. Emerging concepts such as digital twins, Industrial IoT, telemedicine, precision agriculture, and fail‐operational systems are changing the approach toward the design of electronics and telecommunication systems, opening the way to new markets and applications that were unimaginable only a few decades ago. The urgence for pervasive real‐time monitoring systems is pushing technology beyond its current limits, raising new challenges for both academic and industrial R&D labs.

In this context, wireless sensors and RFID technologies can offer very effective solutions provided that their design and implementation take into account the characteristics and constraints imposed by the envisioned applications. For both wireless sensors and RFID devices the use of radiofrequency (RF) technologies is pivotal not only for enabling the data transfer but also for sensing and energy scavenging. While the simplicity and the high performance of RF devices in free space and line‐of‐sight (LOS) are well known, the situation is quite different for real applications that can include the presence of lossy materials, non‐LOS communication, metallic elements, and so forth. Therefore, in most applications the real environment is very different compared to free space and introduces severe propagation conditions from an electromagnetic point of view. Additionally, harsh environmental conditions, such as high temperatures or humidity, can challenge electronics operation, calling for new materials and design approaches.

This book is aimed at both doctoral students and engineers developing R&D projects about wireless and RFID technologies. It provides a unique source of examples of successful wireless system solutions leveraging RFID technologies and similar energy‐efficient wireless approaches, enabling the implementation of advanced concepts such as Internet of Things (IoT) in severe and harsh environments. Indeed, while several literatures on wireless technologies and RFID systems are available and can be considered for the design of basic systems mostly in controlled environments (i.e. anechoic chambers) and academic labs, only a few focus on the actual implementation of advanced and effective solutions in real environments. In real applications wireless sensors and RFIDs have to communicate their information by means of RF signals which propagate in heterogeneous and complex environments. The presence of metal, liquids, biological tissues, plants, and so forth cause significant degradation, distortion or even cancellation of the RF signals, not to mention the detuning effects on the antenna and on the other RF signal components that are generated by the presence of heterogeneous objects in the application environment. Real environment exhibits severe behavior for electromagnetic signals and RF devices. The same characteristics are encountered in harsh environment where high temperatures, strong radiation, and corrosive materials are present. Last but not least, wireless systems that operate in real applications have to comply with the constraints imposed by standards and regulations which are rarely considered in controlled environments.

The book covers the recent advances in wireless and RFID systems where severe electromagnetic behavior and harsh conditions are taken into consideration, while complying with RF standard and regulations. So, this book provides the reader with the design rules and methodologies to obtain satisfactory performance and possibly avoid the typical oversights and mistakes that can be made when first approaching to this topic.

The book is organized in 12 independent chapters grouped in 3 sections. The first section is dedicated to RFID design approaches to implement passive wireless sensors able to operate in harsh and severe environments. This section includes 6 chapters concerning different use cases, which are briefly described herein below:

Chapter 1 entitled “UHF RFID Identification and Sensing for the Industrial Internet of Things (I‐IoT).”

This chapter analyzes the challenges for the successful integration of RFID sensor networks within the industrial and consumer IoT contexts. The challenges in RFID sensor networks encompass robust communication links and accurate sensing measurements. Industrial applications confront additional difficulties due to wireless powering in presence of lossy mediums and metallic objects, compounded by high temperatures and sensor placement on fast‐moving mechanical parts. Temperature impacts sensing ICs, reducing communication ranges, and affecting performance. External probes connected via analog front ends experience stronger temperature sensitivity, causing nonlinear drift. Monitoring high‐speed components introduces further issues, including backscattering link robustness and data transmission/decoding issues, exacerbated by electromagnetic noise from high‐power motors. Ensuring data integrity across the IoT platform necessitates comprehensive security assessments. Adopting new‐generation of microchips with sensing capabilities and low‐power encryption algorithms for data security requires careful evaluation, considering implications for power consumption and data rates. All these challenges are carefully described in the chapter, and possible countermeasures are highlighted.

Chapter 2 entitled “RFID Sensing In Power‐Plant Generators and Power Transformers.” The harsh environment in this chapter is predominately represented by the dense metallic parts which need to be monitored wirelessly. Such environments hinder the antenna performance. In addition, fast rotating parts cause mechanical stress on potential sensors, and the high electric/magnetic field needs to be taken into consideration when selecting the antenna. To tackle the aforementioned harsh environment impact, there are specific choices to be made: the antenna structure should offer good performance when positioned on metallic surfaces, the weight of a potential sensor should be minimized to avoid adding extra strain to the rotating system and loop antenna types must be avoided since they can be current generated by the movement inside of a high magnetic field. Overall, solutions are shown, which are dictated by the expected environment of operation.

Chapter 3 entitled “Design of Passive UHF RFID Sensors Meeting Food Industry Regulations.” RFID tags transformed into sensors sensitive to certain parameters of their environment must be produced in large quantities and at low cost. These requirements can affect measurement reliability, especially in harsh environment conditions. The solutions presented in this chapter aim to avoid this lack of reliability and could therefore be considered for a variety of applications. So by using a simple RFID antenna and a suitable RFID chip, the described systems are easy to duplicate and can be used in groups. Food products are delivered as batches and are separated at the very end in the delivery to the consumer. Although monitoring until the purchase is of interest, it is essential during the first few hours/days of transport, because if the repeated exchanges between the various logistics partners and the exponential growth of micro‐organisms. Furthermore, unlike many RFID systems, the described solutions are independent of external databases. This is an advantage, especially in crowded electromagnetic or severe environments.

Chapter 4 entitled “Challenges of Using RFID for Outdoor Environmental Monitoring.” The deployment of RFID tags outdoors brings a new spectrum of technical difficulties that must be overcome. The presence of water rain, dew, snow, or frost on tags usually decreases signal strength and modify phase difference of arrival, by coupling with the tag antenna. In the far field, propagation through non‐air mediums such as soil, water, snowpack, snowy terrains, or vegetation increases loss, phase delay and multipath interferences. These conditions make it challenging to reliably use passive tags outdoors for localization, sensing but also identification. In this chapter all these challeges are accurately described, with the aim to provide an estimate of the performance loss.

Chapter 5 entitled “Harmonic Transponders for Tracking and Sensing.” This chapter is dedicated to a special category of backscatter radios, called harmonic transponders. Harmonic transponders can operate in environments characterized by strong reflections and metal parts, which are particularly severe for signal propagation, as the contribution from the tags can be easily separated from the rest of the reflections. Additionally, due to their simple circuitry (they are usually based on single diodes), they are particularly robust, which makes them good candidates to operate in environments characterized by harsh conditions (such as low or high temperature, high humidity, and so forth), thereby expanding the possible fields of application of wireless sensors.

Chapter 6 entitled “Passive Wireless Sensors in Radiation Environments.” This chapter examines the radiation environment and its impact on passive/batteryless wireless sensors using the ultrahigh frequency (UHF) radiofrequency identification (RFID), specifically the ramifications of radiation on electronic devices. The chapter explores the use of RFID sensors in radiation environments, including potential radiation effects on RFID tags and methods for protecting these tags against radiation damage. In particular, the discussion links the fundamentals of radiation effects in CMOS circuits with the architectural characteristics and operation features of the RFID tag chip frontends, going down to the circuit block level. Although RFID sensor tags are not yet widely used in radiation environments, there is promising potential demonstrated by existing sensor tag prototypes. These prototypes have successfully addressed major issues, such as tight power constraints resulting from batteryless operation and harsh radiation environments caused by ionizing radiation. Signal‐pattern‐based sensor tag systems have proven particularly successful in areas such as wireless power transfer, setup independence, and robustness in moderate static multipath environments. Additionally, using scaled CMOS for RFID chips and their passive operation is a promising trend that offers a certain degree of radiation hardness.

The second section entitled chipless includes four chapters, dedicated to wireless sensors based on both surface acoustic wave (SAW) and RF resonators, as reported hereafter:

Chapter 7 entitled “SAW Devices Combining RFID and Sensor Functionalities for Harsh Environments.”

This chapter is dedicated to provide an introduction to the surface acoustic wave (SAW) sensors. In our modern society, due to the development of the Internet of Things (IoT) or the industry 4.0, the continuous monitoring of physical data has become a real need. This is still a challenge in harsh environments such as high‐temperature environments or difficult to access environments. Thanks to an electro‐mechanical conversion, the surface acoustic wave (SAW) technology enables to overcome the limits of conventional sensors. Indeed, SAW sensors are passive systems and thus there is no embedded electronic and no need to regularly replace the battery. Thanks to their small size they can be placed in small and tight spots or even work as abandoned sensors (buried sensors for example). SAW sensors can also be remotely interrogated and can thus offer exciting perspectives for remote monitoring and control of moving parts.

Chapter 8 entitled “Wireless Sensing for Harsh and Severe Environments Based on SAW Sensors.”

Surface acoustic wave (SAW) sensors are able to measure various physical parameters like temperature, pressure, and stress without an external power supply. This type of sensors can withstand high temperatures (up to 600 °C), voltages up to 530 kV, currents up to 20 kA, as well harsh chemical environments (heavy fuel oil, SF6 gas, or mineral oil). Therefore, sensors based on SAW technology are used in specific harsh environments like ship engine room, medium‐ or high‐voltage electrical equipment either air‐ or gas‐insulated switchgears or oil‐filled circuit‐breakers. These environments contain many metallic parts where the sensors can be placed, which in some scenarios involve movement, as well as the presence of chemical. The proximity of metallic parts in motion or chemical in different states, with a temperature and age‐dependent complex permittivity, in the vicinity of the antenna associated with the SAW sensor can modify its input impedance leading to a significant measurement error. Actual SAW transducers are described in this chapter, and their performance are toroughly discussed.

Chapter 9 entitled “Microwave Encoders for Motion Control and Chipless RFID Applications.” This chapter presents microwave encoder systems for motion control. They represent an interesting option over optical (encoder) systems based on a similar principle, due to the fact that microwaves are more tolerant to the effects of dirtiness and pollution, as compared to optical radiation. Namely, if the apertures in optical encoders are clogged, the system cannot exhibit its functionality, contrary to microwave encoders, more robust against the effects of pollution and dirtiness. Such harsh and polluted environments are encountered in many industrial systems, and, for this reason, microwave encoders are especially suited in such applications.

Chapter 10 entitled “Chipless RFID Technology for Operations in Harsh Environments.” There are two main relevant aspects of this chapter that deals with the benefit of using chipless RFID sensors. On the one hand, the chapter addresses the different wireless sensor paradigms, namely surface acoustic wave sensors, near‐field ones as well as far‐field radio frequency backscattering. Moreover, it puts in evidence the advantages with respect to solutions that resort to wired connection to recover the data at the sensor or solutions that require batteries. On the other hand, several application domains are addressed (space, oil and gas, automotive, industrial tools monitoring) and great attention is paid to the employed materials.

The third section is entitled systems. It includes two chapters and is dedicated to the impact of specific environments on system based on wireless and contactless devices. Chapter contents are briefly described herein after:

Chapter 11 entitled “Energy‐Autonomous Wireless Architectures for Predictive Maintenance in Harsh Closed Applications”.

In the application described in this chapter, the sensor nodes are placed all around an electromagnetically harsh environment full of metal parts, and they are energized remotely by RF sources operating in the Industrial, Scientific and Medical (ISM) 2.4 GHz band; these sources act as “illuminators,” and a multitude of wireless batteryless sensor nodes are placed in the key points of the bonnet, in contact with parts of the car that need to be monitored. These spaces are generally made of metallic parts, creating an environment that is hostile to the electromagnetic fields. Suitable solutions are described and their performance is discussed.

Chapter 12 entitled “Implanted NFC Tags: Study of Energy Harvesting and Reading by Means of Smartphones.” This chapter describe an IoT solution for implanted electronics based on near‐field communication (NFC). Information gathering from implanted electronics is hampered by a number of factors, including poor coupling due to the vastly different sizes of the reader and the tag antennas; the unknown position of the implanted device causing misalignment; the constrained quality factor of the communication bandwidth; the detuning of the antennas; and, most importantly, the effects of the body that increase the losses, degrading the quality factor of the antenna. The implanted electronics as well as its antenna must be properly protected to ensure proper operation for a sufficient amount of time. To avoid infections, these protections must also be biocompatible. Consequently, the electrical properties of the antenna are modified. Maximum power transfer to load design should be taken into consideration to effectively power the implanted electronics since the power source comes from the smartphone. Consequently, it is crucial to know the NFC IC input impedance. Hence, considering this type of design, the modeling of the IC presents another issue because of its non‐linear behavior. Finally, the presence of ferrites in the smartphone, which allows its antenna to be electrically isolated from the battery and other metallic parts, affects the separation between the mobile and the implant, since they are directly linked to the coupling coefficient.

Smail Tedjini and Valentina Palazzi

Section 1RFID

1UHF RFID Identification and Sensing for the Industrial Internet of Things (I‐IoT)

Carolina Miozzi, Sara Amendola, Cecilia Occhiuzzi, and Gaetano Marrocco

Tor Vergata University of Roma and RADIO6ENSE S.r.L., Roma, Italy

1.1 Introduction

Internet of Things (IoT) is currently considered the paradigm for the next applications in gaming, leisure, and home automation [1] and is expected to also foster changes in modern medicine, manufacturing, energy, agriculture, and transportation, especially thanks to synergy with the upcoming Fifth/Sixth Generation (5G‐6G) wireless communication systems [2]. Indeed, the ability to wirelessly interconnect humans, objects, and machines promises unprecedented technical and economic opportunities in many industrial branches [3]. The capabilities to control complex industrial systems and predict events are enabled by properly processing data gathered directly from surrounding environments and machines in operation, with a positive impact on production, safety, and overall efficiency. This particular implementation of IoT, denoted as Industrial IoT (I‐IoT), refers to highly reconfigurable wireless sensor networks that affect the costs, energy, and procedures of the manufacturing process. By adding novel sensors to existing machinery without significantly modifying current architectures, their functionalities (retrofit) will be upgraded to achieve, over the long term, a fully automated, networked, and data‐oriented industry [4].

In the last decade, energy‐autonomous wireless sensors for ambient monitoring, personal tracking, [6] and manufacturing control have greatly benefited from the well‐assessed Radio Frequency Identification (RFID) standard known as EPC C1G2, which nowadays enables sensing functionalities [7], [8, 9] in addition to basic identification. RFID‐based sensors require relatively limited maintenance compared to other wireless technologies such as ZigBee, Bluetooth, or WiFi [10]. The required energy is provided by external interrogators that can power and interact with a multiplicity of sensors at a time, thus enabling a single‐to‐multipoint link with a remarkable reduction in overall wiring. In addition to passive RFID analog tags that take advantage of interactions between the antenna and the environment to indirectly collect sensing information [11], digital sensor tags equipped with dedicated sensors are becoming attractive for real applications [12]. The latter incorporates ICs provided with internal sensors (generally low‐medium temperature sensors) and analog/digital front end to connect a variety of external low‐power devices. Therefore, several physical parameters can be monitored: high temperature (>80 °C), humidity, and pressure are among the most required in the industrial field. The relatively low cost and maintenance of such tags, their versatility in use and application, and not least, the possibility to exploit conventional RFID readers and standard protocols are expected to boost the massive integration of RFID platforms in industrial scenarios, from automotive to hot/cold manufacturing, from logistics to predictive maintenance. Early studies envisage UHF RFID as a pillar for the implementation of physical or perception layer of the monitoring platforms [9], especially when active devices are not acceptable in terms of size (e.g. for integration within objects), costs, and operating conditions (severe thermal and mechanical stresses ) or in general, when battery replacement is not easy. Recent use cases have proven the effectiveness of RFID sensor networks in the food sector [13], pharma [14], chemical industry [15], and smart grids [16].

The large amount of data generated from these physical sensing layers can be exploited to build a digital representation of plants, machinery, and products, the so‐called digital twins, in which the physical operation process is virtually judged, analyzed, predicted, and optimized and then transferred back to the physical world to execute the optimized solutions [17]. For this purpose, RFID sensor networks must be integrated within cloud‐based infrastructures, in which big data can be efficiently processed according to data‐driven approaches. Taking advantage of the ability of the modern reader to transmit the data collected through many different communication protocols, for example, MODBUS [18], TCP/IP [19], OPC‐UA [20], or MQTT [21], interoperability between platforms, technologies, and monitoring layers is achieved, with benefits in terms of effectiveness of action, usability, and cost optimization.

To establish an efficient monitoring platform through RFID sensors, a robust communication link is required, regardless of the operative conditions of the networks. In fact, in industrial scenarios high temperatures, mechanical solicitations, electromagnetic interference, and the massive presence of lossy and scattering objects such as water and metal could sensibly impact the communication capabilities of sensors, especially in case battery‐less configurations are adopted [9]. Operability in a harsh environment has been partially investigated for HF tags subjected to freezing cycles and exposure to gamma irradiation [22] and UHF tags subjected to high‐temperature cycles (20–180 °C) combined with immersions in water [23]. Similarly, the effects of weather conditions and exposure to washing cycles have been investigated in [24] and [25], respectively. The results suggest that RFID tags can withstand high‐temperature cycling, but the simultaneous presence of water may jeopardize their reliability and sensibly reduce the read distance [26]. Scattering and shielding objects often impose coverage optimization through the selection and positioning of ad hoc reader antennas, such as high‐directive arrays or omnidirectional monopoles. Additional difficulties arise in the case of moving machinery and objects or when the asset to be monitored is enclosed in shielding cavities. In such cases, the reader antennas need to be placed in close proximity to the tags, that is directly integrated within the shielding.