| 摘要 |
<p>An FM diversity receiver system (12) and method which include two antennas (16, 18) and a switch (20) for switching the receiver from one antenna to the other. A fade control signal is produced which is related to the received FM signal, in which fade control signal both multipath and non-multipath disturbances are manifested. Disturbances in the fade control signal are compared (90) with a threshold voltage and, when the disturbance exceeds the threshold voltage, antenna switching is momentarily prevented to prevent antenna switching in response to electrical noise impulses, such as ignition noise, which are shorter than the period during which antenna switching is momentarily prevented. If the fade control signal disturbance continues to exceed the threshold voltage after the momentary period of disablement, the threshold voltage is reset to a level related to the maximum level of the fade control signal disturbance, after which antenna switching takes place. Antenna switching then is again momentarily prevented; this time to prevent antenna switching in response to switching transients produced during the antenna switching operation.</p> |
