Patent ID: 8226003

Claim:
A radio frequency identification (RFID) reader comprising: a radio frequency (RF) antenna; a transmitter section coupled to the RF antenna and operable to generate a transmit RF signal in a transmit path to be transmitted by the RF antenna; a receiver section coupled to the RF antenna and operable to receive a receive RF signal from the RF antenna in a receive path and downcovert the received signal to an in-phase baseband signal and a quadrature baseband signal; a digital signal processor operable to detect phase shifts, generated by components in the receive path, in the in-phase baseband signal and the quadrature baseband signal, substantially decouple the in-phase baseband signal and the quadrature baseband-signal based, at least in part, on the detected phase shifts, and generate an in-phase control signal and a quadrature control signal; a first splitter configure to pass at least a portion of the transmit RF signal in the transmit path to a quadrature modulator; the quadrature modulator configured to generate a reduction signal based, at least in part, on the portion of the transmit RF signal and the in-phase control signal and the quadrature control signal and pass the cancellation signal to a second splitter; and the second splitter configured to combine the reduction signal with the receive RF signal in the receive path, the reduction signal configured to reduce the leakage signal in the receive path of the reader.