Single-source formulation for the analysis of electromagnetic penetrable objects

Abstract

Modified global surface impedance (MGSI) formulation, a fast and efficient single-source integral equation for analyzing penetrable objects including plasmonic circuits and dielectric periodic structures, is proposed. Using the equivalence principle, a single-source formulation for the exterior region of the desired problem is constructed. Then the assumed equivalent source (surface electric current) is written as the sum of two surface electric currents, one related to the other based on the global surface impedance (GSI) model. Thus, the conventional surface integral equation (SIE) for the exterior problem will be modified by this new single-source formulation. The interior problem is also formulated using the GSI model resulting in our proposed MGSI formulation. MGSI eliminates the need for equivalent magnetic current in the SIE formulation. It also helps one to formulate the interior and exterior problems independently. Moreover, in our approach material property does not affect the problem convergence behavior, while the convergence behavior of the conventional SIE deteriorates for a plasmonic structure and also for a dielectric object with high contrast to its surrounding medium. The accuracy and efficiency of the proposed formulation are demonstrated by comparing its results with the conventional SIE in solving several two-dimensional examples.