| 摘要 |
PROBLEM TO BE SOLVED: To provide a pre-selector whose operation state is confirmable without stopping an operation of a reception system and without performing removal from the reception system.SOLUTION: A pre-selector includes a coupler unit, a filter unit, and an amplifier unit. The coupler unit includes a first coupler that couples a diagnosis input signal, which is supplied from a diagnosis device in a frequency band set in advance, to an input RF signal. The filter unit includes a bandpass filter, in which the frequency band is set as a passband, and performs band limitation on the RF signal by means of the bandpass filter. The amplifier unit includes an amplifier that amplifies the RF signal having undergone the band limitation, and a second coupler that extracts the diagnosis input signal from the amplified RF signal. The coupler unit outputs the diagnosis input signal extracted by the amplifier unit to the diagnosis device as a diagnosis output signal. |
