Patent ID: 6259900
Filing Date: 2001-07-10
Classification: H04B

Abstract:
A radio transmitting/receiving apparatus for transmitting/receiving a signal through a microwave circuit, comprising:a signal folding-back circuit for inputting a transmission signal with a frequency different from that of said radio transmitting/receiving apparatus to a radio frequency line of a receiver of said radio transmitting/receiving apparatus through a directional coupler;a first band-pass filter and a second band-pass filter, connected in parallel, for passing a reception signal received from another radio transmitting/receiving apparatus and a transmission signal with a frequency different than a frequency of said reception signal, respectively;a filter selector for selecting said first band-pass filter in a normal state and for selecting said second band-pass filter in a radio frequency signal folding-back test state;wherein a transmission side directional coupler receives a transmission signal of a local station,wherein a frequency shifter converts the frequency of the transmission signal,wherein a reception side directional coupler inputs an output signal of the frequency shifter to a radio frequency line of the receiver of the local station, andwherein said second band-pass filter passes the transmission signal through a reception signal first converter.