An improved subgridding method with the second-order accurate FDTD technique at the dielectric interface

The second-order accurate FDTD technique at the dielectric interface is applied into the subgridding method. The second-order accuracy of the tangential electric fields at the interface can be implemented and the accuracy of the subgridding algorithm is improved. Numerical simulations of dielectric resonators are carried out and the better accuracy is shown in the proposed method than the standard FDTD methods.