A Singularity Cancelation Transformation for Entire-Domain Analysis of 2-D Structures With High-Precision Integration

An approach to singularity cancelation by a variable transformation of Green’s function in 2-D case, having log(
$R$
) singularity, is outlined. It is intended for the method of moments analysis of 2-D structures of both curvilinear and flat cross sections. If the transformation is used with Legendre or Chebyshev polynomials as entire-domain basis functions, all involved integrals can be calculated with high precision using Gauss–Legendre quadrature. The optimal parameter of the transformation, having the minimal number of integration samples needed to reach 14-digit precision, is provided. Error estimations are presented for calculated current distributions on strips up to 400 wavelengths wide, analyzed with up to 1500 entire-domain basis functions.