Design of Cruciform Directional Couplers in E-Plane Rectangular Waveguide

This paper proposes a new type of compact waveguide directional coupler, which is constructed from two crossed e-plane rectangular waveguide with two metallic posts in the square junction and one metallic post at each port. The metallic posts in the square junction are set symmetrically along a diagonal line to obtain the directivity properties. The metallic post inserted at each input/output waveguide port can realize a matched state. Tight-coupling properties 0.79-6dB is realized by optimizing the dimension of the junction and the positions/radii of the posts. The design results are verified by em-simulator (Ansoft HFSS)