Carrier and Noise Cancellation Effects in a Self-Jammer Canceller for UHF RFID Readers

摘要

Self-jammer is the key bottleneck in designing high performance ultra-high frequency (UHF) RF identification (RFID) readers, which may saturate the receiver. In addition, its phase noise and amplitude noise will desensitize the receiver. A self-jammer canceller (SJC) is usually employed in UHF RFID readers to deal with these problems. In this paper, the carrier and noise cancellation effects in a SJC is analyzed. It shows that the maximum noise rejection ratio is limited by the amplitude and phase errors of the cancellation path and leakage path, while the noise rejection bandwidth is determined by the relative delay between the two paths. The analyzed results are verified by simulations and measurements.