Calculation of the inner EFIE integral over a bilinear quadrilateral to machine precision

We present a new method for calculating the inner integral of the matrix element in the application of the method of moments to the Electric Field Integral Equation. The geometry panels are bilinear quadrilaterals (BQ) and the basis functions are polynomials. We show that the unstable part of this two-dimensional integral can be reduced analytically to a one-dimensional integral that can be stabilized to provide numerical results to double precision.