Analysis of lossy waveguide circuits by the BI-RME method and a perturbation technique

In this paper the extension of the Boundary Integral-Resonant Mode Expansion (BI-RME) method to the modeling of lossy waveguide components is discussed. The proposed technique is based on the combination of the BI-RME method and of a perturbation approach. The generalized admittance matrix of the circuit, which is provided by the BI-RME method as a pole-expansion in the frequency domain, is perturbed to account for both metallic and dielectric losses. Since the BI-RME method applies to homogeneously filled waveguide components, a segmentation technique is adopted in case of a piece-wise homogeneous dielectric medium. The effectiveness of the proposed technique is demonstrated through examples.