Fast and accurate finite-element and boundary-integral method for scattering by complex targets

This paper studies in detail a variety of formulations for the hybrid finite-element and boundary-integral (FE-BI) methods for three-dimensional (3D) electromagnetic scattering by inhomogeneous objects. A new formulation is then proposed and numerical results show that the resulting solution has a good efficiency and accuracy and is completely immune to the problem of interior resonance. The multilevel fast multipole algorithm (MLFMA) is employed to significantly reduce the memory requirement and computational complexity of the proposed FE-BI method. The scattering by several typical targets is computed by this method, demonstrating the accuracy and efficiency of this proposed MLFMA-enhanced FE-BI method.