Solving scattering from 3D composite conducting and dielectric object by surface integral equation method

Recently, scattering from 3D composite conducting and dielectric object receives much attention. Traditionally, FEM-BI method is applied to solve the problem. But absorption boundary condition (ABC) is needed in FEM-BI method. In this paper, we use two combinations of surface integral equation to solve the RCS of 3D composite conducting and dielectric object. Fast multipole method (FMM) is used. The problem is formulated in terms of a set of coupled integral equations involving equivalent electric and magnetic surface currents based on the equivalence theorem. The conducting structures and the dielectric materials are modeled by planar triangular patches, RWG basis and Galerkin method are used. The fast multipole method is applied to accelerate the computation of matrix-vector multiplication. The computational complexity and storage requirement is O(N^1.5), respectively. Numerical results are given for various structures and compared with other available data. The numerical results show that the present method has satisfying accuracy.