An efficient approach for computing scattering by inhomogeneous objects with thin dielectric structures

This paper incorporates the compensated Mitzner boundary conditions (CMBC) into the hybrid finite element- boundary integral-multilevel fast multipole algorithm (FE-BI-MLFMA) for fast and accurate computation of scattering by three-dimensional inhomogeneous objects with thin dielectric structures. In this CMBC-FE-BI-MLFMA, each thin dielectric layer is reduced to an interface with zero thickness; then CMBC is applied to establish the relation of electromagnetic fields across the interfaces. This approach can reduce the amount of computation and remain the advantages of versatility, accuracy, and efficiency of the conventional FE-BI-MLFMA algorithm. The formulation of this CMBC-FE-BI-MLFMA is presented in this paper. An efficient preconditioner based on the sparse approximate inverse is employed and further parallelized on memory-distributed platforms. Numerical results are presented to demonstrate the accuracy, efficiency, and capability of the parallel CMBC-FE-BI-MLFMA.