{"title":"Passive Chipless RFID Tags for Humidity Sensing: A Review","authors":"Chitturi Suneel Kumar;Situ Rani Patre","doi":"10.1109/JRFID.2025.3562719","DOIUrl":"https://doi.org/10.1109/JRFID.2025.3562719","url":null,"abstract":"This review paper presents comprehensive literature on passive chipless Radio Frequency IDentification (RFID) humidity sensor tags, including working principle, performance measures, and use cases. The RFID humidity sensor tag comprises of RF resonators for identification and separate resonators along with smart material for humidity sensing. The humidity sensor tags are effective permittivity-based sensors, where the smart material’s effective permittivity changes with humidity. The change is recorded with different coding methods, whereas the sensitivity depends on both tag configuration and sensing material. Therefore, this paper emphasizes state-of-the-art tag configurations, approaches to designing RFID humidity sensor tags, and the properties of the humidity-sensitive material. Most of the RFID humidity sensors are designed based on the frequency coding method where coding capacity depends on the number of resonators, hence the overall size of the tag. Therefore, a variety of resonators like patch- and slot-types, along with their orientation with respect to linearly polarized reader antenna are discussed. The advantages of slot-type tags coated with humidity-sensitive material are highlighted in terms of dual-side readability, polarization-independent nature, higher data coding capacity, and better sensitivity. RFID humidity sensors will be beneficial for future Internet-of-things (IoT) applications.","PeriodicalId":73291,"journal":{"name":"IEEE journal of radio frequency identification","volume":"9 ","pages":"200-214"},"PeriodicalIF":2.3,"publicationDate":"2025-04-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143896264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Human Activity Recognition: A Review of RFID and Wearable Sensor Technologies Powered by AI","authors":"Ria Kanjilal;Muhammed Furkan Kucuk;Ismail Uysal","doi":"10.1109/JRFID.2025.3561345","DOIUrl":"https://doi.org/10.1109/JRFID.2025.3561345","url":null,"abstract":"Human activity recognition (HAR) has garnered significant attention across diverse domains such as fitness enhancement, safety, elderly care, clinical monitoring, and smart environments. However, despite its potential, HAR faces challenges like handling noisy and diverse data, ensuring real-time performance, maintaining user privacy, and achieving high accuracy across varying contexts and activities. A primary challenge of HAR lies in maintaining consistency and accuracy during data collection amidst varied activities and environments. This review article provides a comprehensive overview of the advancements in AI-enhanced HAR methods, with a focus on radio frequency identification system, wearable devices, and smartphone sensor technologies. We delve into the frameworks of these technologies, detailing processes like data collection, preprocessing, and the application of machine learning and deep learning algorithms. Additionally, we outline the advantages and drawbacks of these techniques and provide a brief comparison between them.","PeriodicalId":73291,"journal":{"name":"IEEE journal of radio frequency identification","volume":"9 ","pages":"180-199"},"PeriodicalIF":2.3,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143883365","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"MU-MIMO for Passive UHF RFID","authors":"Ryan Jones;Shuai Yang;Richard Penty;Michael Crisp","doi":"10.1109/JRFID.2025.3561497","DOIUrl":"https://doi.org/10.1109/JRFID.2025.3561497","url":null,"abstract":"Radio Frequency Identification (RFID) is frequently deployed in high tag density environments, where tag read rate can become a limiting factor. Current Class 1 Gen 2 (C1G2) RFID systems are limited in read rate by the Framed Slotted Aloha (FSA) scheduling algorithm and physical layer modulation parameters. We propose a multi-user MIMO (MU-MIMO) RFID system compatible with C1G2 which enables simultaneous communication with multiple tags, achieving greater read rates. Multiple monostatic reader antennas are exploited to recover collided tag data and perform channel estimation. These channel estimates are then used to precode the reader’s ACK signals across multiple transmit antennas into spatial channels such that the tags will receive separated acknowledgements. To evaluate potential performance gains, we calculate theoretical throughput improvements and empirically measure the signal-to-interference ratio (SIR) required for commercial passive tags to respond to collided acknowledgements. Furthermore, we perform simulations to determine the effect of increasing number of tag responses on channel estimation accuracy, and hence the received SIR at tags. An experiment is carried out using two monostatic transceivers with two emulated tags, showing successful channel recoveries and uncollided reader acknowledgments commands at the tags, and hence compatability with C1G2 protocol provided a reader can be developed meeting the timing requirements.","PeriodicalId":73291,"journal":{"name":"IEEE journal of radio frequency identification","volume":"9 ","pages":"215-226"},"PeriodicalIF":2.3,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143896542","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Compact Folded Dipolar Patch Antenna With Broad Tuning Range for On-Metal Tag Design","authors":"Subbiah Alagiasundaram;Kim-Yee Lee;Eng-Hock Lim;Pei-Song Chee","doi":"10.1109/JRFID.2025.3561277","DOIUrl":"https://doi.org/10.1109/JRFID.2025.3561277","url":null,"abstract":"A compact dipolar patch antenna, which is embedded with a middle-layer patch internally, is proposed for designing an on-metal tag. Multiple tuning mechanisms have been employed for enabling frequency tuning over a wide bandwidth. First, the antenna’s shorting stubs are displaced diagonally to two opposite corners for lengthening the current paths. Then, the two patches are coupled capacitively for generating additional tuning reactance. Finally, multiple inductive slits have been incorporated with the patches for lowering the tag’s resonant frequency. Employment of the tuning mechanisms has successfully brought the tag resonance down to the UHF RFID passband. Notably, adjusting the slit length <inline-formula> <tex-math>$(i_{2})$ </tex-math></inline-formula> allows the tag’s resonant frequency to be tuned across a broad range from 834 MHz to 964 MHz. Despite its compact size of <inline-formula> <tex-math>$25times 25times 3.3$ </tex-math></inline-formula> mm3, the proposed tag can be read from a distance of 16 m (with 4W EIRP), which is much longer than most of the contemporary on-metal tags of this size.","PeriodicalId":73291,"journal":{"name":"IEEE journal of radio frequency identification","volume":"9 ","pages":"170-179"},"PeriodicalIF":2.3,"publicationDate":"2025-04-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143883334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"A High-Reliability PUF Solution for Securing RFID Systems Against Machine Learning","authors":"Abolfazl Rajaiyan;Yas Hosseini Tehrani;Seyed Mojtaba Atarodi","doi":"10.1109/JRFID.2025.3560996","DOIUrl":"https://doi.org/10.1109/JRFID.2025.3560996","url":null,"abstract":"For Radio Frequency Identification (RFID) security, reliable keys are essential. Physical Unclonable Functions (PUFs) prevent physical cloning, but they are sensitive to environmental variations and vulnerable to Machine Learning (ML) attacks. In this paper, a security system is proposed that aims to generate keys with high reliability and resistance to ML attacks. The entire system can be integrated into RFID tags. For reliable key generation, the proposed approach utilizes a two-step structure comprising a Coarse PUF and a Fine PUF, along with modified Ring Oscillator (RO) PUFs featuring varying ring counts. This design enhances resistance to machine learning (ML) attacks through challenge obfuscation. To further improve security against ML attacks, real-time power consumption is monitored using a novel analog circuit, and a hardware algorithm is developed based on the monitored power data. The proposed PUF (128-bit key generator) is implemented on an FPGA from the Xilinx family, specifically the Zynq-7 model. The robustness of the proposed PUF is evaluated through voltage and temperature variation tests. Experimental results demonstrate a Bit Error Rate (BER) of <inline-formula> <tex-math>$3.42times 10^{-5}$ </tex-math></inline-formula>, with uniqueness and uniformity values of 49.77% and 50.27%, respectively. While a conventional PUF exhibits a vulnerability of 91.23%, the implementation of the proposed system and hardware algorithm reduces this vulnerability to 50.17%. The obtained results confirm that the proposed system offers a significantly more secure and robust solution compared to other competitors.","PeriodicalId":73291,"journal":{"name":"IEEE journal of radio frequency identification","volume":"9 ","pages":"161-169"},"PeriodicalIF":2.3,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143875107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Karl Adolphs-Saura;Ferran Paredes;Amirhossein Karami-Horestani;Pau Casacuberta;Paris Vélez;Ferran Martín
{"title":"Phase-Modulation All-Dielectric and “Green” Electromagnetic Encoders for Motion Sensing and Near-Field Chipless-RFID","authors":"Karl Adolphs-Saura;Ferran Paredes;Amirhossein Karami-Horestani;Pau Casacuberta;Paris Vélez;Ferran Martín","doi":"10.1109/JRFID.2025.3560736","DOIUrl":"https://doi.org/10.1109/JRFID.2025.3560736","url":null,"abstract":"In this paper, a new electromagnetic encoder system for motion sensing and near-field chipless-RFID applications is presented. The system consists of an encoder, based on chains of transversally oriented linear apertures in a dielectric substrate, and a reader with an open-ended quarter-wavelength resonator that is sensitive to the presence of the apertures. The reader can detect variations in the phase of the reflection coefficient due to the motion of the encoder. To validate the encoder system, two encoders are implemented in a low-loss rigid substrate, and four are fabricated in flexible substrates, such as paper and plastic (polyethylene terephthalate -PET). One of the rigid encoders is incremental (with a periodic chain of apertures) and the other one is quasi-absolute (with two aperture sizes), useful for both motion sensing and near-field chipless-RFID. For the encoders implemented in flexible substrates (quasi-absolute in all cases), the apertures are replaced with linear chains of small holes, with a period of <inline-formula> <tex-math>${p}{=}2$ </tex-math></inline-formula>.3 mm. The resulting density of bits per unit length is DPL <inline-formula> <tex-math>${=}4.35$ </tex-math></inline-formula> bit/cm. Such encoders provide a means to implement cost-effective and eco-friendly (“green”) systems.","PeriodicalId":73291,"journal":{"name":"IEEE journal of radio frequency identification","volume":"9 ","pages":"146-160"},"PeriodicalIF":2.3,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143875272","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Innovations in RFID and Wireless-IoT: Advancements in Smart Technologies and Sensing Applications Guest Editorial of the Special Issue on SpliTech 2024 Conference","authors":"Luca Catarinucci;Andrea Ria;Arnaud Vena","doi":"10.1109/JRFID.2025.3553925","DOIUrl":"https://doi.org/10.1109/JRFID.2025.3553925","url":null,"abstract":"","PeriodicalId":73291,"journal":{"name":"IEEE journal of radio frequency identification","volume":"9 ","pages":"123-125"},"PeriodicalIF":2.3,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://ieeexplore.ieee.org/stamp/stamp.jsp?tp=&arnumber=10949084","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143777781","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Differential RCS of Multi-Port Tag Antenna With Synchronous Modulated Backscatter","authors":"Nicolas Barbot;Ionela Prodan;Pavel Nikitin","doi":"10.1109/JRFID.2025.3557078","DOIUrl":"https://doi.org/10.1109/JRFID.2025.3557078","url":null,"abstract":"This paper introduces a new method, called multi-port load modulation, allowing one to improve the delta RCS of any passive transponder. By switching simultaneously the loads connected to a multi-port antenna, we show that the associated delta RCS can be higher than the one predicted by the equations of R. Green in 1963. We demonstrate analytically that the delta RCS of the multi-port tag can be improved by 6 dB compared to a single port antenna. This improvement corresponds to an increase of the round-trip read range of 41%. This result can still be improved if the modulation of the structural mode adds constructively with the modulation of the antenna mode. Simulation and measurement of a fully compliant dual-port tag validate the model and achieve a large part of the predicted improvement.","PeriodicalId":73291,"journal":{"name":"IEEE journal of radio frequency identification","volume":"9 ","pages":"126-134"},"PeriodicalIF":2.3,"publicationDate":"2025-04-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143817831","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"BLE-Driven Power-Efficient Integrated Sensing and Communication Framework for Livestock Monitoring","authors":"Lalit Kumar Baghel;Radhika Raina;Suman Kumar;Riccardo Colella;Luca Catarinucci","doi":"10.1109/JRFID.2025.3554569","DOIUrl":"https://doi.org/10.1109/JRFID.2025.3554569","url":null,"abstract":"The existing BLE-based cattle health and activity monitoring solutions rely primarily on parametric power optimization. However, a cattle health and activity monitoring system may require non-optimized parameters. Further, existing solutions transmit raw data, which is usually generated frequently, consequently increasing total transmission and causing high power consumption. Besides, BLE-based solutions are prone to data loss as the number of devices in the network increases, necessitating multiple transmissions to overcome data loss. However, the lack of an analytical framework to determine the optimal number of retransmissions results in redundant transmissions. This highlights the need for analytical expressions to precisely calculate the required number of retransmissions to overcome data loss. Owing to this issue and the emergence of BLE-related solutions, we have first examined the root cause of higher power consumption. Secondly, to reduce the number of transmissions causing major power consumption, we have proposed a threshold mode that reduces the total number of transmissions and saves a significant amount of power by only transmitting parametric data over raw data, which is usually sensed and transmitted very frequently. Thirdly, we have derived analytical close-form expression for the average number of transmissions required for successful data reception, which was the critical bottleneck in existing works. As a result, we have achieved significant improvement in battery life over the existing works; in particular, we achieved a maximum battery life of 10 years in mode A (raw data transmission) and 21 years in mode B (thresholding mode).","PeriodicalId":73291,"journal":{"name":"IEEE journal of radio frequency identification","volume":"9 ","pages":"135-145"},"PeriodicalIF":2.3,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143856377","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"An IoT-Based RFID Solution for Peer-to-Peer Surveillance of Warehouse Using a Novel Antenna Sensor","authors":"Aijaz Ahmed","doi":"10.1109/JRFID.2025.3553151","DOIUrl":"https://doi.org/10.1109/JRFID.2025.3553151","url":null,"abstract":"This work presents a novel methodology of an RFID system for peer-to-peer surveillance of products in warehouses. The methodology also uses a novel antenna sensor that continuously senses the tags/ products within its radiating field region. This designed antenna sensor works in a dual frequency range of 865–867 MHz and 902–928 MHz with a peak gain and typical VSWR of 3.9 dBi and 1.05 respectively. To demonstrate the proof of concept of the methodology, 4-identical antennas are fabricated and stacked on the racks where the products along with tags are used to be placed. These tags are being monitored by the server that compares the ordered products with the collected products from the shelves and raises the warning or an alarm when any unwanted tags is moved or missing from the locations on the shelves. Multiple measurements are performed to check the accuracy and repeatability of the system with random positions of the tags. The outcome validates that the proposed antenna, along with the developed methodology, can be used in warehouses for monitoring the positions of the products as well as in the peer-to-peer surveillance of products if they have any unauthorized movements from the shelves.","PeriodicalId":73291,"journal":{"name":"IEEE journal of radio frequency identification","volume":"9 ","pages":"117-122"},"PeriodicalIF":2.3,"publicationDate":"2025-03-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143726580","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}