An RFID transceiver device is capable of high sensitivity reception, by
the reduction of noise, irrespective of the distance to the tag. The RFID
transceiver device includes a delay circuit between a local oscillation
circuit and a demodulation circuit, wherein the amount of delay of the
delay circuit is set to a magnitude corresponding to the path difference
between the path of leakage, via a duplexer into the demodulation
circuit, of transmission signal output from the local oscillation circuit
for transmission, and the path of direct input of the local oscillation
signal from the local oscillation circuit to the demodulation circuit.