A Reconfigurable 6-Bit Chipless RFID Sensor for Humidity Detection
Yi Wang, Luyi Liu, Bo Wang, Mei Song Tong · 2024
Radio frequency identification technology is widely applied in sensors due to its capability of identify multiple targets at same time with high efficiency. Among the research areas of RFID technology, chipless RFID technology is a widely concerned topic, since the lower cost after removing the embedded chips. In this paper, a configurable chipless radio frequency identification (RFID) senor is demonstrated. It is designed based on microstrip patch antenna. On both sides of the patch, six in total, S-shaped split ring resonators (S-SRRs) are located to construct the trap circuit. Besides, PID diode is added in each resonator to achieve reconfigurability. The parameters of resonators are optimized, and six different states of the tag are reported. One resonator coated with humidity-sensitive material, works as sensing unit. Simulated result of resonance frequency shifting with the humidity is presented. Therefore, it has the potential of sensing moisture in environment and working in various scenarios counting on its reconfigurable design.