Well-Conditioned FEM-BEM-DDM for Electromagnetic Scattering by Composite Objects

The domain decomposition method(DDM) based on the hybrid finite element-boundary element (BEM) is presented for simulating electromagnetic scattering problems in this paper. In this method, the first order Robin-type transmission condition (RTC) is used to connect the interfaces of FEM and BEM regions and the second order transmission condition (SOTC) is used to joint the interfaces in interior FEM regions. The ingredients of this paper are as follows. First, the combined field integral equation (CFIE) is applied into FEM-BEM-DDM. Second, the conditioning of the discretized matrix equation can be essentially improved and rapidly converging iterative solutions can be obtained by properly choosing the coupling coefficients of the equations.