Amrita Pati
Ansys Employee

Hi Ceshi,

You can use 2D simulation region if the structure has a translational symmetry along one of the axes. In your case since the structure is not uniform along the third axis, a 2D simulation region should not be used. If it was a hexagonal prism of infinite length then 2D FDTD would have been accurate. So, for 2D simulation you can assume that the structure is infinitely long and uniform.