Design of A Terahertz Waveguide Bidirectional Coupler

A terahertz (THz) waveguide bidirectional coupler with compact, wide bandwidth and high directivity was designed. Based on the multi-hole coupling theory, HFSS software was used to simulate and optimize the THz waveguide bidirectional coupler. A three-layer structure design scheme is proposed to solve the problem of insufficient precision of four-layer structure through waveguide, realize the continuity of waveguide structure and improve the insertion loss of coupler. The developed THz bidirectional coupler has a frequency range of 500GHz-750GHz, the insertion loss is less than 5dB, and the directivity is better than 23dB.