Chipless RF Identification Sensors for Product Tracking and Identification Applications: A Review

RF identification (RFID) technology is finding significant use in the development of massive low-cost sensor networks. The advantages of RFID sensors, which include being passive, less expensive, and lower maintenance, are driving their mass deployment. RFID sensors offer the ability to capture an enormous amount of information from the environment, making them especially attractive in healthcare, smart homes, the Internet of Things (IoT), banking, and transportation. Chipless RFID (CRFID) sensors are a type of RFID sensor that has found applications in wireless and nonintrusive health monitoring and product identification and tracking. This article reviews recent advances in the field of CRFID sensors. CRFID sensors are currently being employed to monitor humidity, temperature, strain, and metal failure; for wearable and touch sensing; and for applications that entail monitoring multiple parameters. They are also suitable for real-time operation and can be seamlessly integrated into existing systems, supporting improved product quality, system efficiency, and safety in sectors that range from healthcare to manufacturing, logistics, and retail. Limitations of CRFID include a small read range, lower data storage capacity and sensitivity, and the risk of tag collision and signal interference. To address these limitations, we propose research in advanced signal processing techniques, robust anticollision protocols, new materials for tag durability, and efficient anticollision strategies that consider tag density and memory constraints. Once these problems are addressed, CRFID sensors should find many industrial applications that contribute to the development of IoT systems and smart infrastructure. This review will be useful to both researchers and industry professionals who are interested in using CRFID technology to improve efficiency and productivity.