| 摘要 |
<p>PURPOSE:To enable normal decoding without saturating the reception part of a responsor even when an interrogator and the responsor are close to each other by outputting a detection signal when the distance calculated by an arithmetic circuit is smaller than a preset saturation occurrence distance. CONSTITUTION:When a question signal is sent from the interrogator 1 and identification information on a mobile station is obtained from an answer signal to the question during a communication between the interrogator 1 arranged in a base station and the responsor on the mobile station such as an aircraft and a vessel, the arithmetic circuit consisting of the decoder 1g, etc., of the interrogator 1 calculates the distance between the interrogator 1 and responsor 2 from the time required for the sent question signal to travels to and return from the responsor 2. A control circuit 4b compares the calculated distance with the preset saturation occurrence distance to detect the calculated distance is smaller in such a case, and outputs the detection signal. Further, an attenuator 1c reduces the output of the transmitter 1b on the side of the interrogator 1 by an attenuator according to the detection signal from the control circuit 4b.</p> |
