RFID READER CANCELLING LEAKAGED SIGNAL

摘要

An RFID reader for offsetting transmission leakage signals is provided to reduce the whole power consumption by cancelling the transmission leakage current by the control of a digital unit. An RFID reader comprises a digital unit(370) which calculates the amplitude and phase of a transmission leakage signal, and stores the calculated result, and a leakage offsetting circuit(330) which generates a leakage offset signal in response to the control of the digital unit, wherein the leakage offset signal has the same amplitude as that of the transmission leakage signal and has a phase reverse to that of the transmission leakage signal. The leakage offsetting circuit receives a local oscillation signal from a frequency synthesizer(350), and then generates the leakage offset signal.