To provide a transmission reception module that applies fault diagnosis to a transmission reception function during an actual operation so as to detect the occurrence of the fault thereby detecting in which of the transmission function or the reception function the fault takes place.
The transmission reception module is provided with: a transmission antenna for emitting a received transmission signal into air; a reception antenna; a detector for obtaining a DC voltage proportional to the input signal; a coupling circuit for entering part of the transmission signal received by the transmission antenna to the detector and outputting the part to a monitor terminal; a reception amplifier for amplifying the input signal and outputting the amplified signal; a changeover device for entering either of the output of the monitor terminal and the output of the reception antenna to the reception amplifier; a mixer for mixing the output of the reception amplifier with the transmission signal; and a detection circuit for detecting the output signal of the mixer to monitor the output level of the monitor terminal.
Tadahiko Inaba
Kanako Murakami
Nakatsuru Kazutaka