Study on 220-GHz Confocal Gyro-Amplifer Circuits with Wedges-Loaded Mirrors

This paper proposes a confocal waveguide circuit with stability-enhanced structure for practical applications. Two pairs of metal wedges attached to both sides of mirror plates are introduced. They have an effect on guiding the radiation wave along the wedge wall, keeping the outward wave from directly coupling back into the circuit region. In this way, the unwanted pipe modes in the vacuum cavity can be effectively suppressed. Results indicate that a tilt angle of about 50° works well to suppress the pipe cavity modes, which is able to improve the stability of gyro-amplifiers.