| 摘要 |
PURPOSE:To make no noise component based on switching of an antenna appear an audio component in the detection output, by switching the antenna electronically at a high speed simultaneously with the detection of a multipath noise. CONSTITUTION:When receiving by the antenna 6, if the influence of a multipath appears in the output waveform A, and a noise component appears in the detection output C, the mulitpath detection circuit 8 provides a switching control signal F to the switching means 9. The means 9 is provided with two control input terminals, and control signals of opposite phase to each other, based on the signal F are applied to said two input terminals. In response to this control signal, the means 9 switches the antenna from 6 to 7 electronically at a high speed, for instance, 10musec or <5musec preferably. Accordingly, since the antennas 6, 7 are switched instantaneously as soon as a multipath noise is detected, a noise component based on this switching is not superposed as an audio component on the detection output. |
