The numerical solution of electromagnetic integral equation in frequency domain based on higher-order basis functions

This paper adopts the surface triangle and Curved quadrilateral mesh subdivide boundary surfaces of the conductor. For discretization of the surface integral equation of electromagnetic field in using moment method, high order triangular basis functions and curved quadrilateral base function are used. Further, using the relationship between the dispersion of surface charge density and the higher order function and through coordinate transformation methods, the singularity of surface integrals is removed. The key of numerical solution of frequency domain electromagnetic integral equations is to calculate the impedance elements. When the source and field surface triangle coincide, the integrand has singular points in the domain. In order to eliminate the singular points of the integral, in plane RWG discretization, the method of addition and subtraction singular terms are used to the singularity elimination. But in the use of curved basis function method, in order to improve the computational efficiency, unit surface of the target unit is much larger than the traditional method of moments, this should not be used and singular method. In this paper, using parametric representation of the surface triangle or curved quadrilateral, then mapped to the plane square, finally through a set of linear transform, singular integral can be removed.