| 摘要 |
PURPOSE:To effectively reject the interference waves, by adjusting the voltage fed to the varactor element of the first or second phase shifter depending whether the control voltage is more than a given level or not. CONSTITUTION:The antennas 1a and 1b are provided on equi-wave surfaces for desired waves and on different propagation distance for interference waves, and the capacitive components of the output signal of the antennas 1a, 1b are fed to the variable phase shifters 4a, 4b of LPF type constituted with the varactor element of voltage control type. Further, the output signals of the phase shifters 4a and 4b are synthesized and picked up from the transmission path. In this case, DC control voltage is superimposed on the transmission line to separate the control voltage, and the voltage having a given amount level or more fed to the varactor element of the phase shifter 4a is adjusted, and it is fed to the varactor element of the phase shifter 4b when the level of the control voltage is less than a given amount to adjust the voltage. Thus, the interference waves can effectively be rejected. |
