Numerical Analysis of Scattering from the Edge-Type Scatterer in a Rectangular Waveguide by the Yasuura Method.

The Yasuura method (mode matching method) was applied to the problem of electromagnetic wave scattering by an obstacle in a rectangular waveguide to prove the usefulness of this method as a general-purpose analysis method. In this paper, the scattering problem of an inductive obstacle with edges placed in a rectangular waveguide is analyzed numerically, taking into account the singularity of the solution at the edges. The inductive obstacle is considered to be a perfect conductor with an asymmetrical triangular cross section with an arbitrary apex angle. Each comer of the triangle is treated as a singularity. The algorithm is presented which takes into consideration the singularity of the solution at the edge, and then the accuracy of the analysis is discussed. As a numerical example, the frequency characteristics of reflection and transmission coefficients versus various parameters are shown including the behaviors of higher-order modes. By taking advantage of the fact that the magnitude of the apex angle can be changed arbitrarily, the effect of the slant angle of the triangle on the incident side exerted on the scattering is discussed. Since the structure can be computed for an apex angle starting from 0°, the solution for an apex angle of 0° or the inductive window is compared with the exact solution by Wiener-Hopf method so that the analysis error is carried out. [ABSTRACT FROM AUTHOR]