TRANSMISSION/RECEPTION DEVICE

摘要

A transmission filter allows a signal in the frequency band of a transmission signal to pass through the transmission filter and blocks signals in other frequency bands. The transmission signal output from the transmission filter is supplied to an antenna via an antenna sharing device and transmitted to the outside. A reflected-signal detector senses the amplitude and the phase of a reflected signal from the antenna and outputs detection signals (DA and DP). A control circuit adjusts control signals (CA and CP) on the basis of the detection signals (DA and DP). A cancellation-signal-output circuit adjusts a cancellation signal in such a manner that the cancellation signal has a phase opposite to that of the reflected signal and an amplitude the same as that of the reflected signal by using the control signals (CA and CP). A multiplexer combines the cancellation signal with a received signal including a noise signal.

主权项

1. A transmission/reception device comprising:
a transmission circuit; a reception circuit; an antenna; an antenna sharing device connecting the antenna to the transmission circuit and connecting the antenna to the reception circuit; reflected-signal-detection means disposed between the antenna sharing device and the antenna and detecting a reflected signal, wherein the reflected signal is a part of a transmission signal output from the transmission circuit and reflected by the antenna; a duplexer disposed between the antenna sharing device and the transmission circuit and retrieving a signal from the transmission signal; a cancellation-signal-output circuit outputting a cancellation signal used for cancelling the reflected signal based on the signal retrieved by the duplexer; a multiplexer disposed between the antenna sharing device and the reception circuit and combining the cancellation signal with a received signal to be input to the reception circuit; and a control circuit controlling the cancellation-signal-output circuit, wherein the control circuit adjusts an amplitude and a phase of the cancellation signal based on an amplitude and a phase of the reflected signal detected by the reflected-signal-detection means.