Modeling of waveguide components by the BI-RME method with the Ewald Green's function and the segmentation technique

This paper presents a novel technique for the numerical modeling of three-dimensional waveguide components. The component is preliminary segmented into boxed building blocks, and then the generalized admittance matrix of each building block is determined by the Boundary Integral-Resonant Mode Expansion (BI-RME) method. The kernel of the integral equation is the Green's function of the box, which is efficiently calculated by using the Ewald technique. Finally, the admittance matrices of the building blocks are cascaded to retrieve the frequency response of the whole component. The analysis of a dual-band orthomode transducer is reported as an example, demonstrating the effectiveness of the proposed algorithm.