Efficient analysis of coated object using fast algorithm with surface impedance boundary condition

An effective solution method is proposed to analyze the electromagnetic scattering problem of coated targets, which is based on a novel form of multilevel matrix decomposition algorithm (NFMLMDA). It uses an efficient directional grouping scheme to subdivide the far -field domain, and then a novel distribution form of equivalent source is applied to reduce the matrix filling time and memory requirement. By using the grouping scheme, the far -field interaction domain can be divided into many cone structures. The matrix between the observation group and far -field group in the cone structure is low -rank, which meets the directional far -field requirement. Meanwhile, the impedance boundary condition (IBC) is applied to simplify the solution process and improve the accuracy of the approximate solution. The method of this paper is very suitable for the needs of various kinds of complex problems.