| 摘要 |
PURPOSE:To always use a communication system in a good quality state by measuring transmitting waves connected to the same antenna system by means of a receiving system connected with the antenna system and monitoring an external feeder and impedance of the antenna. CONSTITUTION:A transmission system is constituted of transmissionsystem filters 1 and transmission-system circulators 2 and a reception system is constituted of reception-system filters 3, a filter 8, and reception-system circulators 4. A feeder 6 and antenna 7 constitute an external antenna system. The filter 8 provided at the tail end of the reception branching filter system blocks received waves, but passes arbitrary one or plural transmitting frequencies of the transmission system being energized by the external feeder 6. Accordingly, when the output of the filter 8 in connected to a power measurement instrument 9, observation can be carried out even when the impedance of the feeder 6 and antenna 7 changes. Therefore, the quality of the communication line can always be maintained in a normal state. |
