Calculation of physical optics integrals over electrically large NURBS surface illuminated by a Gaussian beam for reflector antenna applications

For reflector antenna applications, a method for calculation of physical optics (PO) integrals over electrically large nonuniform rational B-spline surfaces illuminated by a Gaussian Beam is presented in this paper. This method has efficient advantages and its computation cost does not increase with frequency. The highly oscillatory PO integral is calculated with delaminating quadrature method. The influence of critical points is taken into account by subdividing the integral intervals. Numerical examples are presented to validate this approach.