TIME DIVISION MULTIPLEXING CONNECTION TRANSCEIVER AND ITS RECEIVING AUTOMATIC GAIN CONTROL METHOD

摘要

A RF switch (12) is connected to a receiving section (2) on receiving timing. A RF signal received by an antenna (11) is input to an amplifying section (5) via an isolator (3) and a RF filter (4), automatically amplified in gain, and input to a demodulating section (6). A received signal level is sensed by a RSSI61: if the sensed value exceeds a threshold value, a demodulator (62) controls the RF switch so as to switch to a transmitting section (7) free of transmission output. As a result, the input of the receiving section is attenuated largely. The isolator maintains a matching of an amplifying section input impedance regardless of the switching condition of the switch and secures low-noise and safety.