HF RFID transponder with capacitive coupling

HF RFID transponders with capacitive coupling were made. They have two electrodes for capacitive coupling instead of a coil for magnetic induction coupling. Prototypes of capacitive coupling transponder communicate via a medium composed of conductors and/or dielectrics normally existing around us. In HF band, since the human body is also a conductor and a dielectric, RFID communication can be carried out through the human body. Transponders with capacitive coupling have the possibility to widen the application of RFID and realize more natural and intuitive applications. In this paper, the measurement results of the antennas specially designed for capacitive coupling are reported. Characteristics unique to capacitive coupling type RFID on human body are also described. In particular, the influence of individual differences and the result of examination about correspondence to RFID regulations indispensable for practical application are introduced.