摘要 |
<p>The present invention discloses methods and an apparatus for characterizing an antenna system. The apparatus comprises a processor (108), a coupler (116), and a converter (122). The processor (108) selectively injects a test signal (114) into amplifiers (106) in the antenna system while other amplifiers (106) are amplifying the broadcast signal (112), and the amplified signals are then fed to a hybrid matrix (104). The coupler (116) samples the combined amplified test and broadcast signals, and the converter (122) converts the combined test and broadcast signals to a different frequency band to separate the test signal (114) from the broadcast signal (112). The processor (108) determines a phase response and an amplitude of a first amplifier (106A) and a phase effect of the hybrid matrix (104) by measuring the separated test signal and modifies a phase of the broadcast signal (112) using the determined phase response of the first amplifier (106A) and the hybrid matrix (104) when the broadcast signal (112) is subsequently provided to the first amplifier (106A). <IMAGE> <IMAGE></p> |