Mode Matching Analysis of an E-Plane $90^{\circ }$ Bend With a Square Step in Parallel-Plate Waveguide

We present a numerical model for the analysis of an E-plane right-angle bend in parallel-plate waveguide (PPW), with a single square step for matching purposes. This design can achieve wideband matching and can be implemented using hollow waveguides as well as multilayer printed circuit boards. An even-and odd-mode analysis is performed exploiting the symmetry of the structure. Two auxiliary problems are defined considering the bisecting plane of the bend as a perfect electric conductor or a perfect magnetic conductor, respectively. They are solved using a mode matching method. The mathematical derivations are discussed in detail. The proposed procedure can be embedded in efficient tools for the analysis of complex PPW systems, such as feed networks for antenna arrays.