A novel microwave limiter with non-reciprocal limiting threshold is
proposed in this paper to protect the transceiver switch or the
transmitter. The directivity of the directional coupler is utilized to
make the power of the received signal input to the detection circuit
larger than that of the transmitted signal, thereby the detection
circuit provides different DC bias voltage to the limiter circuit and
changes the threshold level of the limiter diode. The test results show
that this limiter has a threshold level of 35 dBm for the transmitted
signal and 17 dBm for the received signal, which has a non-reciprocal
limiting threshold for high-power signals input in both directions.