| 摘要 |
PURPOSE:To reduce variation in the gain of a receiver due to temperature change by feeding back a control signal based on the amplitude of noise detected during the time other than the listening time of a radar receiver to a receiver gain controlling circuit. CONSTITUTION:The noize amplitude 13 out of the listening time T of a radar is fed via a gate control signal (c) from a second gate 8 as a gain compensating video (e) to a stretching circuit 10, which stretches the noize amplitude. The stretched noize amplitude is further converted through a low pass filter 11 into a DC voltage. An amplifier gain control signal is fed back to the gain controlling circuit of a radar receiver contained in an amplifier 6 to retain the DC voltage constantly by a control signal generator 12 so as to suppress the variation in the gain due to the temperature change of the radar receiver to the degree of variation in the thermal noize. On the other hand, a video within the listening time T is fed via a gate control signal b to a signal processor 9, and an AGC is executed with the received vodeo signal to the amplifier 4. The AGC is so conduced as to be applied thereto only during the listening time. |
