3D hybrid ADI-FDTD/FDTD subgridding scheme applied to RF/microwave and optical structures [waveguide/cavity examples]

In this paper, a 3D hybrid FDTD and ADI-FDTD technique is proposed. In it, the ADI-FDTD is applied to the fine mesh and FDTD to the coarse mesh. A subgridding interface is then developed and the associated interpolation is applied in the space domain only. This technique is efficient for applications in which there is need of fine subgrids. It leads to savings in memory and computation time. Examples are shown for validation purposes.