| 摘要 |
PURPOSE:To attain excellent communication by providing a directional coupler between a transmission antenna and a transmission section of a radio station and between a reception antenna and a reception section and connecting a phase shifter-attenuator controlled by a controller to the coupler so as to prevent mutual interference of adjacent frequencies between radio stations. CONSTITUTION:The directional couplers C1, C2 are connected respectively between the transmission section T1, the reception section R2 of the base stations B1, B2 and the antennas A1, A2. The phase shifter-attenuator D where the phase shift amount and the attenuation are varied is provided between the couplers C1 and C2. Moreover, a controller CTR and a test switch TS are connected between the transmission section T1 and the reception section R2 of the base stations B1 and B2. The phase shifter-attenuator D is controlled automatically by the controller CTR so that the signal receiving amount of the reception section R2 is minimized by the operation of the switch TS. Thus, the mutual interference of adjacent frequencies between the base stations B1 and B2 is prevented and excellent communication is attained. |
