Evaluating Singular and Near-Singular Integrals in RCS Calculation

For the method of moments (MOM) based on curvilinear Rao-Wilton-Glisson (CRWG) basis function, an efficient method is developed to solve the singular and near-singular impedance elements. In this paper, detailed treatment of the use of singularity subtraction methods on curvilinear triangular elements is given, and it is shown how singularity subtraction integral rules derived on planar triangular elements apply to curvilinear triangular elements. Numerical examples of RCS calculation demonstrate the correctness and efficiency of this method.