| 摘要 |
The present invention provides a demultiplexer/multiplexer having: an input terminal for receiving an input signal from each phase of a quadrifilar helical antenna; a first phase-shifting/separating/mixing unit that applies 90/-90° phase shifts alternately to the right-handed circularly polarized waves and the left-handed circularly polarized waves of the input signals of phase 1 and phase 2 in in-phase combinations and combines the signals; a second phase-shifting/separating/mixing unit that applies 90/-90° phase shifts alternately to the right-handed circularly polarized waves and the left-handed circularly polarized waves of the input signals of phase 3 and phase 4 in in-phase combinations and combines the signals; a first phase-shifting/mixing unit that receives the left-handed circularly polarized waves, applies 180/-180° phase shifts in an opposite-phase combination of one of the signals and the other, and combines the signals; a second phase-shifting/mixing unit that receives the right-handed circularly polarized waves, applies 180/-180° phase shifts in an in-phase combination of one of the signals and the other, and combines the signals; a variable phase shifter that adjusts one output signal with a pre-received amount of phase shift; and an output terminal for outputting the output signal of the variable phase shifter and the other output signal that has not been input to the variable phase shifter. Thus, it is possible to reduce a multipath effect acting on the quadrifilar helical antenna. |
