An Efficient Numerical Method for Solving Multiscale Electromagnetic Scattering Problems

Abstract

An efficient numerical method is proposed to compute the multiscale eletromag-netic scattering problems in this paper. The complex structures are decomposed into several parts and each subdomain is discretized independently. The proposed method relies on using characteristic modes (CM)as macro basis functions which is refered as characteristic mode basis functions (CMBFs)for each subdomain of the object. Each CMBF can be expanded as a linear combination of RWG basis functions and half RWG basis functions which are defined on the boundary edges between adjacent subdomains. It should be noted that CMBFs can be reused when the subdomains share identical or scaling contour feature. In this way, the CMBFs need to be calculated only once for scaling subdomains. Furthermore, rotated subdomain like aircraft's propeller owns the same CMBFs at different rotating angles. Since the number of modes used for each subdomain is much samller than the number of RWG and half RWG basis functions, this metod can lead to a reduced matrix system where the number of unknowns is drastically decreased. In addition, by adopting discontinuous Galerkin schme, the proposed method can handle both conformal and nonconformal discretizations along the tearing lines. (Delete this sentence with red color)Numerical results demonstrate that the proposed method is efficient and accurate in analyzing the multiscale problems.