Treatment of Singular Integrals on Generalized Curvilinear Parametric Quadrilaterals in Higher Order Method of Moments

Singular integrals over the generalized curvilinear parametric quadrilaterals in higher order method of moments (MoM) are treated by a singularity cancellation technique. The singularities are eliminated via coordinate transformation, by which the singular integrals are converted into some regular integrals that can be numerically computed by using the Gauss-Legendre quadrature. Numerical results show that this proposed singular integral treatment approach converges much faster, yet achieves several orders of magnitude higher precision than the widely used singularity subtraction technique.