An Approximate Algorithm for Transient Near Field Scattering from a Rough Surface in 2-D Mode

An approximate algorithm is proposed to improve the computational efficiency for analyzing the transient near-field electromagnetic (EM) scattering from a rough surface in two-dimensional (2-D) mode, which is a combination of the time domain physical optics (TDPO) with the time domain Huygens principle. In this scheme, the equivalent EM currents and charges on rough surface are computed by applying the TDPO method. The near-field radiation of these equivalent sources is solved in marching-on-in-time way based on the time domain Huygens principle, where the semi-analytical recursive convolution (SARC) scheme is utilized to reduce the computational cost of the convolution integration of equivalent source and time domain Green's function based on digital signal processing idea. The proposed hybrid algorithm is validated through the comparison with the finite difference time domain (FDTD) method, indicating its reliability and efficiency in the calculation of the transient near-field scattering from rough surface.