A Novel Hybrid Method of Spatially Filtered FDTD and Subgridding Technique

A novel hybrid method of spatially filtered finite-difference time-domain (SF-FDTD) scheme and subgridding technique is presented to analyze the multiscale objects. Because of the controllable stability of the SF-FDTD scheme, which is applied in the subgrid region, the uniform temporal increment can be employed in the whole simulation region. Therefore, the temporal interpolation of the field components can be avoided at the coarse-dense grids connecting boundary. In addition, by selecting the appropriate spatial interpolation field points in the Yee cells and only eliminating the unstable frequency domain magnetic fields, the influence of the filtering operation at the connecting boundary is removed. The simulation results are presented to validate the accuracy and efficiency of the hybrid method.