Channel switching system without instantaneous signal loss

Abstract

A channel switching system without an instantaneous signal loss in a data communication system such as a digital microwave multiple radio communication system. The channel switching system includes a control unit for generating a switching control signal in response to a fault detecting circuit; a unit for receiving a phase adjustment signal from the active receiver unit of an active transmission channel and another signal from the standby receiver, for adjusting the phases between both received signals in response to the switching control signal, and for outputting a switch energizing signal; a high speed switching unit, including a unipolar high speed switching circuit, for switching signals from the phase adjustment unit in response to the switch energizing signal. The switching system further includes a compulsory switching unit, for compulsorily switching the signals supplied to the switching unit. The phase adjustment unit outputs the switch energizing signal to the unipolar switching circuit when a phase coincidence is obtained before a predetermined time, so that the unipolar switching circuit outputs the phase-adjusted signal. The compulsory switching unit enerigizes the unipolar switching circuit, when the phase coincidence is not obtained during the predetermined time, to output one signal in response to the switch energizing signal.