Patent ID: 6256484
Filing Date: 2001-07-03
Classification: H04B

Abstract:
Apparatus for processing electromagnetic signals transmitted at a carrier frequency over a multipath route, comprising:at least first and second antennas;switch means having a first and second state;means for adding the received signals received by said first and second antennas together to provide a sum signal only when said switch means is in a predetermined one of said first and second states;time delay means for delaying said received signals for at least 90 degrees of a cycle of the carrier wave of said signals when said switch means is in said second state;receiver means for processing said received signals;indicating means for providing a level indicating signal related to the amplitude of one of said received signal and sum signal;said switch means being responsive to said indicating means for selectively switching said switch means between said first and second state;said switch means including first and second conductor means having different amounts of delay and means for detecting the presence of the level indicating signal on both the first and second conductor means wherein said switch means changes state only when said one of said received signal or sum signal drops below a threshold strength.