Design of Simulation Parameters in Angular spectrum Domain for Two-dimensional Mirror Kirchhoff Approximation and Split Step Parabolic Equation

As the prediction methods for the forward scattering problems, the Mirror Kirchhoff Approximation (MKA) and Split Step Parabolic Equation (SSPE) apply a fast Fourier transform (FFT) to achieve a fast prediction. The simulation parameters (i.e., the intervals and windowing functions in the space and angular domains of the FFT) directly determine the accuracy and computational load. This paper reviews the design of the simulation parameters in the angular spectrum domain for the two-dimensional (2D) MKA and SSPE. A 2D elliptical conductor cylinder is used to exam the designed parameters. The method of moment (MoM) is used to validate the accuracy and the uniform theory of diffraction (UTD) is used to compare the calculation time. The results imply that the MKA with the designed parameters can provide a good accuracy within a lower computational cost.