TX-to-RX Leakage Canceler for IoT RFID Applications

The performance of the ultra-high frequency (UHF) radio frequency identification (RFID) systems are usually degraded by inadequate transmitter-to-receiver (TX-to-RX) isolation. In order to tackle this problem, in this paper a broadband leakage canceler is presented. The proposed canceler utilizes a two-stage lumped element Wilkinson power divider and a direct leaky coupling circuit (DLCC) in order to provide a high isolation between the TX and RX paths. The measured results for the implemented leakage canceler are in fine agreement with the simulation results. The fabricated leakage canceler occupies only 53×30×0.8 mm
³
while providing an isolation better than -40 dB in the UHF RFID frequency band of 0.812-0.965 GHz.