Analysis of Post-Wall Waveguide by H-Plane Planar Circuit Approach

A waveguide whose side walls are formed of densely arranged metallic posts has been proposed and applied to antennas etc. for millimeter-wave. This paper suggests an analytical method of the post-wall waveguide or the substrate integrated waveguide by applying the analysis technique of the H-plane waveguide discontinuities based on the planar circuit approach. The analytical procedure consists of the derivation of the mode impedance matrices for regular-shaped circuits and short-circuiting fictitious ports arranged at the peripheries of the metallic posts. First, a straight section of the post-wall waveguide is treated as an example and the analysis method is described. Then the S-parameters of the guide are calculated. Next, the analysis method is applied to the design of a right-angled corner with an air post. The analysis and the design results are verified by an em-simulator (HFSS).