| 摘要 |
PURPOSE:To detect failures of antennas during the operation of radar, by making self-check of an alarm circuit through the detected output of a reflection power of a transmission signal for the purpose of the detection of antenna failure. CONSTITUTION:A transmitted power outputted from a transmitter 4 is applied to an antenna 1 via a transmission/reception switch 3 and a directional coupler 2. The reflection power from the antenna 1 is applied to a wave detector 6 via a wave detector protecting circuit 12 consisting of the directional coupler 2 and an attenuator or a limiter. The output of the detector 7 is applied to a control circuit 11, where failures of the antenna can be discriminated by the output. Thus, since the transmission signal is used, microwave parts are less in number and the cost is low. Since no parts for switching circuit, etc. is required for reception systems 5, 8, the noise index of the reception system can be increased. |
