Parallel SDIE Method Based on CFIE and IBC for Electromagnetic Scattering Analysis of Large-Scale and Nonuniform Coated Objects

Partly and nonuniform coated objects are one type of important targets in electromagnetic (EM) engineering, and their EM scattering characteristics are an aspect of great concern. To efficiently formulate the EM scattering problem of objects with partial nonuniform coating, we propose a new self-dual integral equation (SDIE) by combining the impedance boundary condition (IBC) and the combined field integral equation (CFIE) in a special way. Besides, the discontinuous Galerkin (DG) method is employed to discretize the new SDIE, which can effectively and flexibly deal with the problem of discontinuous surface impedances from nonuniform cases. Numerical experiments have proved the proposed DG-C-SDIE has much more stable convergence than existing integral equation methods for partly IBC objects while ensures high accuracy. To apply DG-C-SDIE method to analyze electrically large coated objects, we hereby further introduce a high-efficiency parallel algorithm of multilevel fast multipole based on MPI and OpenMP schemes to fast solve the matrix equation. With the aid of advanced computers, the parallel DG-C-SDIE method has the ability of dealing with large-scale objects with hundreds of wavelengths.