Thomas Ussmueller
MICROWAVES SEE ICE: ARTWORK BY AYDIN BADRIAN
Within the realm of ever-advancing technology and its ceaseless pursuit of progress, the need for dependable and resilient sensors capable of enduring unforgiving environments has reached new heights. As researchers strive to navigate these challenging conditions, the advent of RF sensors tailored explicitly to such circumstances has emerged as a pivotal turning point. These cutting-edge sensors bestow upon us many advantages, ranging from heightened safety and efficiency to a complete transformation of data acquisition and surveillance. In this focus issue of IEEE Microwave Magazine, organized by Technical Committee 26 (TC-26) on RF Identification (RFID), Wireless Sensors, and the Internet of Things (IoT), we shine a spotlight on four noteworthy research articles that elevate the current standards of RF sensing in harsh environments.
The first article, “Emerging Backscattering Technologies for Wireless Sensing in Harsh Environments” by Salvati et al. [A1], describes various backscattering technologies, including traditional backscatter, harmonic backscatter, and ambient backscatter, explaining their operating principles and characteristics. Examples of these technologies are provided, such as a backscatter system for leaf canopy temperature measurements and a backscatter tag with M-Quadrature Amplitude Modulation. Harmonic backscattering is explored as an alternative to reduce self-jamming, with examples of a passive wireless pressure sensor and a passive temperature sensor.
The next article, authored by Shah et al., “Microwaves See Thin Ice: A Review of Ice and Snow Sensing Using Microwave Techniques” [A2], describes the use of microwave sensors for measuring frost formation, ice, and snow accretion. These sensors provide precise measurements of key parameters within complex mixtures, allowing for the optimization of localized ice sensing and deicing systems. They enable real-time monitoring beneath protective and deicing coatings, offering cost-effective fabrication and seamless integration into a wide range of applications, including monitoring road conditions, aircraft, and wind turbines.
The third article, “Pulsing the Passive RF Identification Technology” [A3], introduces the concept of pulsed wave (PW)-mode signals, explores additional processing at the reader, and discusses the advantages of PW-mode RFID in complex multipath propagation channels. Authored by Ezzeddine et al., the article highlights the exploitation of frequency diversity and introduces the time reversal (TR) mode, which focuses the propagating wave spatially and temporally. The TR mode improves power transfer capacities by designing channel-adapted PW signals. The article concludes by emphasizing the potential of PW-mode RFID in optimizing performance and addressing the challenges posed by complex propagation environments.
In the last article, by Maderböck and Ussmueller, “Multicarrier communication for UHF RFID” [A4], multicarrier communication is demonstrated to increase coverage and reliability in ultrahigh-frequency (UHF) RFID multipath environments. The text explores different approaches, including using multiple carrier frequencies and external signal sources, to overcome this limitation. It also highlights the challenges of multipath propagation and the need for the careful selection of transmission frequencies. The text describes a measurement setup for characterizing the radio channel in UHF RFID systems.
This focus issue has been organized by TC-26 of the IEEE Microwave Theory and Technology Society. The TC focuses on RF technologies in the field of RFID, wireless sensors and the IoT. Members of the committee are working on theory, modeling, system concepts, integration with sensors and power scavengers, low-cost prototyping, and experimental verification.
We hope that you find this topic and these articles interesting and informative.
[A1] R. Salvati, V. Palazzi, L. Roselli, F. Alimenti, and P. Mezzanotte, “Emerging backscattering technologies for wireless sensing in harsh environments,” IEEE Microw. Mag., vol. 24, no. 10, pp. 14–23, Oct. 2023, doi: 10.1109/MMM.2023.3293583.
[A2] A. Shah, O. Niksan, M. C. Jain, K. Colegrave, M. Wagih, and M. H. Zarifi, “Microwaves see thin ice,” IEEE Microw. Mag., vol. 24, no. 10, pp. 24–39, Oct. 2023, doi: 10.1109/MMM.2023.3293617.
[A3] H. Ezzeddine, Y. Merakeb, J. Huillery, A. Bréard, and Y. Duroc, “Pulsing the passive RF identification technology,” IEEE Microw. Mag., vol. 24, no. 10, pp. 2–12, Oct. 2023, doi: 10.1109/MMM.2023.3293613.
[A4] M. Maderböck and T. Ussmueller, “Multicarrier communication for UHF RFID,” IEEE Microw. Mag., vol. 24, no. 10, pp. 51–58, Oct. 2023, doi: 10.1109/MMM.2023.3293636.
Digital Object Identifier 10.1109/MMM.2023.3294899