The transmission circuit which generates the reception mannered null transmission signal of the transmitter-receiver, the RFID system for radio communication

摘要

A transmitter/receiver for radio communication according to an embodiment of the present invention has: a transmission circuit for generating a transmission signal; a demodulation circuit for demodulating a receive signal; an antenna circuit for transmitting the transmission signal from the transmission circuit and receiving the receive signal and guiding the receive signal to the demodulation circuit; a phase shift circuit which is connected between the transmission circuit and the antenna circuit; and a switching circuit which switches between outputting a superimposed signal of the transmission signal and the receive signal between the phase shift circuit and the antenna circuit to the demodulation circuit, and outputting a superimposed signal of the transmission signal and the receive signal between the transmission circuit and the phase shift circuit to the demodulation circuit.