Readiness mode switching unit with low signal attenuation

摘要

The unit has a branching device connected to a normal receiver and a standby receiver, and consists of a coupler and a high frequency (HF) switching unit. A changeover device switches and outputs the normal or standby receiver output. A controller monitors the receiver states and controls the changeover device and switching unit so that for normal states of the normal receiver its output is selected, and the switching unit passes the low and high attenuation outputs to the normal and standby receivers respectively. If the normal receiver fails the unit selects the standby receiver output, and switches the low damping output to the standby receiver, and the high attenuation output to the normal receiver.