| 摘要 |
PURPOSE:To perform detection surely even when a receiving signal has attained a saturation level by detecting that the value obtained by multiplying the number of hits of the receiving signal in a specified time and the max. value of amplitude data attains the max. value. CONSTITUTION:The radio waves from a receiver 62 are subjected to threshold discrimination with a level discriminating circuit 63, and the video signal larger than the threshold level is applied to an analog-digital converting circuit 64 and a counter 65. A multiplier 68 multiplies the max. value of the amplitude of the video signal in a specified time detected with a peak holding circuit 66 and the number of hits in a specified time counted with a counter 65, and applies the multiplied value thereof to a detecting circuit 69 for the time when radio waves are irradiated. In a peak detecting circuit 692, the multiplied value in the central part of a storage area and the multiplied value at both ends of the central part are compared successively, and when the multiplied value of the central part is largest, the time when the radio waves are irradiated is detected and a trigger signal is led out. |
