A generalized total-field/scattered-field plane-wave source for FDTD analysis of rough surface

The conventional total-field/scatter-field (TF/SF) technique is commonly used in electromagnetic scattering simulations, but it has a limitation in that it confines the scatterer within the TF/SF boundary, and thus cannot be employed directly in simulations of infinite rough surfaces. Introducing incident waves accurately and effectively becomes a challenge for the finite-difference time-domain method when dealing with rough surfaces. To address this issue, this paper extends a generalized total-field/scattered-field (G-TF/SF) method that embeds the TF/SF boundary within the convolutional perfectly matched layer to handle three-dimensional (3-D) electromagnetic scattering from rough surfaces. The numerical results demonstrate that the G-TF/SF technique can effectively eliminate the edge effect caused by ground truncation. Moreover, the accuracy of the G-TF/SF method is verified by comparing its simulation results for the flat ground with the theoretical solution. Finally, the G-TF/SF technique is applied to simulate the electromagnetic environment for rough surfaces.