Chipless RFID Tag for Touch Event Sensing and Localization
A novel Radio Frequency Identification (RFID) based sensor supporting touch detection and localization features is proposed in this work. The formulated sensor leverages chipless variant of RFID technology for the design of a passive fully-printable frequency domain-based sensor-incorporated tag. The sensor is composed of square resonators arranged in a peculiar fashion laid down across a 3 × 2 grid. The proposed sensor incorporated-tag readily keeps track of human-digit position, allowing for
... tion, allowing for tracking of finger-swipes which, in turn, can potentially be used for recognition of unlock patterns and security codes. Performance of the sensor is analyzed using its Radar Cross Section (RCS) response observable in the spectral domain. Each constituent resonant-element making up the sensor resonates at a single frequency represented by a distinct dip in the RCS response. The spectral dip drifts well outside of its allocated band upon occurrence of a touch event. A functional prototype of the sensor tag is fabricated on a 0.508 mm thick Rogers RT/Duroid R 5880 laminate is scrutinized of its electromagnetic performance. The sensor possesses a compact physical footprint equal to 45 mm × 55 mm. The obtained results solidify the suitability of the proposed sensor for deployment in secure access control settings prevalent in smart cities and connected home applications. INDEX TERMS Chipless tag, radio frequency identification (RFID), RFID sensor, radar cross-section (RCS), touch sensor. JONATHAN LOO (KOK-KEONG LOO) received the M.Sc. degree in electronics and the Ph.D. degree in electronics and communications from the University of Hertfordshire, U.K., in 1998 and 2003, respectively. He leads a Research Team of eight Ph.D. degree students in the area of communication and networking. He is currently a Professor and the Chair of computing and communication engineering with the School of Computing and Engineering, University of West London, U.K. His research interest includes network architecture, communication protocols, network security, embedded systems, video coding and transmission, wireless communications, digital signal processing, and optical networks. He has successfully graduated 13 Ph.D. degrees as a Principle Supervisor and contributed over 175 publications in the aforementioned specialist areas.