| 摘要 |
PURPOSE:To enable a circuit to operate accurately against multipath disturbances, generated in succession in a short time, by providing a means of discharging instaneously charges accumulated in a storage element for generating the mean level of the envelope of a received signal. CONSTITUTION:Output signal D of monostable multivibrator 9 for multipath disturbance detection signal generation is inputted to FF10 and antenna change-over switch 3 is controlled by the output of FF10. Simultaneously, signal D is applied to switching signal generating circuit 11, which generates and applies switching signal F of narrow width with a prescribed time lag to the base of switching transistor TRQ1. Consequently TRQ1 discharges instantaneously smoothing capacitor C1 for the generation of the envelope mean level of a received signal, so that the multipath disturbance detection circuit can be obtained which can detect multipath disturbances and has high precision. |
