| 摘要 |
<p>PURPOSE:To enable the detection of a target even if a target signal is limited to a threshold level or less, by providing receiving sensitivity before and behind the saturation level of a receiver and comparing the output level thereof with the saturation level of the receiver. CONSTITUTION:At first, when a receiver 4 is not saturated by clutter, the outputs S, R of the receiver 4 and the receiving circuit 9 in a detector 7 become the same and, because the input R of a comparator 11 and the saturation level Sat of the receiver 4 are R<Sat, the comparator 11 turns a gate 12 OFF and the output of a differential amplifier 13 comes to a fixed threshold level Tf to be sent to a detector group 6 and a target signal is detected by said level. Next, when the receiver 4 is saturated by clutter, the output S(=Sat) and R of the receiver 4 and the circuit 9 are different to each other and come to R>Sat and the comparator 11 turns a gate 12 ON while the output R-Sat=CL of a differential amplifier 10 is sent to the amplifier 13 and the output of the amplifier 13 comes to Tf-CL=TC and set to a threshold level and the presence and absence of the target signal is detected by the detector group 6.</p> |
