Perturbation modeling of high-loss waveguide components by the BI-RME method

This paper presents the application of the Boundary Integral-Resonant Mode Expansion (BI-RME) method to the modeling of waveguide components comprising lossy dielectric materials. The proposed technique is based on the combination of the BI-RME method and of a perturbation approach. The BI-RME method yields the frequency response in terms of the generalized admittance matrix, expressed as a pole expansion in the frequency domain. The inclusion of dielectric losses by the perturbation approach is mainly performed by considering the quality factor of the modes of the cavity obtained by short-circuiting the ports of the circuit. The BI-RME method can be applied to waveguide components filled with a piece-wise homogeneous dielectric medium, by adopting the segmentation technique. Two examples are presented to validate the accuracy and robustness of the proposed method.