Flexible GMRES‐FFT method for fast matrix solution: application to 3D dielectric bodies electromagnetic scattering

In this paper, the electromagnetic wave scattering is analysed by the efficient Krylov subspace iterative fast Fourier transform (FFT) technique in terms of the electric field integral equation (EFIE) for a dielectric body of general shape, inhomogeneity, and anisotropy. However, when the permittivity of the scatter becomes large, the convergence rate of Krylov subspace iterative methods slow down. Therefore, the inner–outer flexible generalized minimum residual method (FGMRES) is used to accelerate the iteration. As a result, nearly 10 times convergence improvement is achieved for high permittivity cases. Copyright © 2004 John Wiley & Sons, Ltd.     

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. Copyright © 2016 John Wiley & Sons, Ltd.