Novel double-band input coupler for gyroklystron and gyro-TWT

A novel input coupler that can operate in two different frequency bands separately is proposed in this paper. The dual-band (X/Ku) signals are input by two rectangular waveguides, respectively, in particular, a Bragg reflector is inserted in one of the rectangular waveguides to avoid the electromagnetic backflow, and then the circular TE01/TE02 modes are excited in the cylindrical cavity by field diffraction through the coupling holes with the help of a coaxial cavity. The simulation results show that dual-band input couplers for both dual-band gyroklystron and gyrotron traveling wave tube obtain excellent performance, laying the foundation for the development of the dual-band gyro-amplifier.