High-order locally corrected Nyström solution for the electromagnetic scattering of composite material objects

A high-order locally corrected Nyström (LCN) solution of a combined volume-surface integral equation is presented for the electromagnetic scattering by complex targets that consist of composite homogeneous and inhomogeneous materials and conducting objects. It is found that, for general scattering objects, the use of mixed-order basis functions accelerates the convergence of the LCN solution, eliminates spurious charges, and significantly reduces the condition number of the resulting linear system of equations. Fast iterative solvers based on a multi-level fast multipole method (MLFMM) and the quadrature sampled pre-corrected FFT (QSPCFFT) are also employed to enable the practical solution of large complex targets.