| 摘要 |
PURPOSE:To make it possible to easily change the response time of the change in receiving gain, to change the gain even if S/N is inferior and to make a receiving level constant, by calculation the square average value of error voltage through the comparison of detection output and a reference signal to control a digital attenuator. CONSTITUTION:The time window of a detector 13 is controlled by the signal from a controller 16 corresponding to the altitude and posture of a platform and a part good in S/N is cut off from a receiving signal to perform detection. This detection output and the reference signal from the controller 16 to function in accordance with reference command are compared by a comparator 14 and the controller 16 calculates the square average voltage of the time of time constant of error voltage and further corrects the same corresponding to time constant to control a digital attenuator 11 through a gain setting circuit 17. By this method, a receiving gain response time can be easily changed without using a variable capacitor and the desired setting of gain can be performed even if S/N is inferior and a receiving level can be made constant. |
