Spatial interpolation method for solution of electromagnetic scattering from objects located in half-space

Abstract

Efficient evaluation of spatial Green's functions is a key to solve radiation and scattering from the objects located in half-space by integral equation method. In this paper, tabulation and interpolation for Sommerfeld integrals are discussed to calculate spatial Green's functions for half-space. If the object is located in the same half-space, a 2D interpolation scheme is requested; if penetration occurs, 3D one is requested. In order to reduce the number of sampling points and to obtain better accuracy, a modified interpolation technique is employed to smoothen the interpolated functions from which an oscillatory term or a singular factor is extracted out. Since the proposed method makes the best of the slowly varying spatial characteristics, spatial repetition and cylindrical symmetry of the spatial Green's functions, tremendous computation effort is avoided as well as efficiency of impedance matrix filling is enhanced.