Design of a G-Band Quasi-optics mode converter

The loss of terahertz waves in transmission lines should not be neglected, and the use of Gaussian beam propagation electromagnetic waves can make the energy highly concentrated at the center of the transmission structure, which helps to reduce the loss. In this paper, a smooth-walled dual-mode antenna is designed for receiving Gaussian beams in the terahertz band, which is converted into TE 11 waveguide mode to facilitate subsequent conversion to the mode required for beam-wave interaction in electric vacuum devices. The VSWR of the Gaussian beam reception system in G band designed in this paper is less than 1.06. And the efficiency of receiving the ideal Gaussian beam is more than 93%. The use of this technique will be beneficial to solve the problem of high loss at higher frequency bands such as 1 THz.