Accurate evaluation of singular potential integrals in an asymptotic-phase method of moments formulation

The Khayat-Wilton singularity cancellation technique has been adapted for computing the potential integrals involving the 3D Green's function and the linearly-phased Rao-Wilton-Glisson (GP-RWG) basis functions. The GP-RWG basis functions are used to expand the induced currents in terms of current-modes, which allows an efficient representation of the currents in large scatters using a fewer number of unknowns. The proposed procedure overcomes some drawbacks of other singularity schemes, such as the dependence of the triangular-patch shape and the location of the observation points. In this sense, the proposed procedure is valid for singularities and "near" singularities oil arbitrarily-shaped triangular meshes. This significantly improves the reliability of the method of moments and related approaches in combination with the asymptotic phase formulation when dealing with arbitrary and automatically generated surface meshes. (C) 2007 Wiley Periodicals, Inc.