MLFMA analysis of scattering by conducting objects above a lossy half-space

In this paper, the electromagnetic scattering from an arbitrarily shaped 3-D conducting object located above a lossy half space is analyzed using the multilevel fast multipole algorithm (MLFMA). In order to use the MLFMA, a higher order approximation method is used for evaluation of the spatial domain half-space Greenpsilas functions for the far interactions, with the resulting construction applicable to the addition theorem expansion. The purposed method can yield highly accurate results with small group size of the MLFMA and can be easily operated. Numerical results are presented to demonstrate the accuracy and efficiency of the proposed method.