Simulation of output coupler in a 170 GHz confocal gyro-TWT

The open sides of confocal waveguide diffract the spurious modes and operating mode at the same time. The operating mode must be converted to Gaussian mode to avoid transmission loss during a long transmission length. The transmission loss was analyzed and a simple output coupler was designed to convert the confocal TE
₀₆
mode to circular TE
₀₃
mode in this paper.