Propagation modeling using the Split Step Fourier method: Ground boundary conditions analysis and acceleration by GPU

Forward propagation above dielectric surfaces is studied using the Split Step Fourier (SSF) resolution technique. The introduction of Fresnel Boundary Conditions (SSF-FBC) and Leontovitch Boundary Conditions (SSF-LBC) is described. The numerical singularity induced by the reflection coefficient at pseudo-Brewster incidence is analyzed, and the DMFT solution for SSF-LBC resolution is retrieved. The limit induced by the Leontovitch assumption is studied on typical grounds. Numerical validations of the proposed method are presented by comparison with the asymptotic formulation. As the SSF is based on an FFT algorithm, the acceleration using a GPU implementation is studied and the numerical time gains are given.