Multi branch Waveguide Coupler for400GHz Broadband

This paper presents a multi-branch waveguide coupler designed for 400 GHz broadband applications. The coupler structure is based on a rat-race coupler topology, and it is optimized with respect to bandwidth and insertion loss. The proposed design was fabricated and measured, and the results confirm the coupler's excellent performance in terms of bandwidth and insertion loss. This study demonstrates the feasibility of using multi-branch waveguide couplers for 400 GHz broadband systems.