H-Matrix-Based Direct Solver of JMCFIE for the Analysis of Scattering From Penetrable Objects

Method of moments (MoMs) solution of the electric and magnetic current combined-field integral equation (JMCFIE) for penetrable objects generally resorts to iterative solvers, which suffer from the problems of convergence rate and redundant computation for multiple right-hand-sides (RHSs). In this communication, an efficient direct solver based on the hierarchical (
$\mathcal {H}$
-) matrix technique is presented to solve these problems.
$\mathcal {H}$
-matrix formatted algorithms provide an efficient way to factorize the impedance matrix with low computational costs, which make the direct solution feasible. Examples of electromagnetic scattering from a dielectric object and optical scattering from a plasmonic nanostructure are shown to demonstrate the efficiency and accuracy of the proposed method.