Errors in the shielding effectiveness of cavities due to stair-cased meshing in FDTD: Application of empirical correction factors

The errors, due to stair-cased meshing, in the Shielding Effectiveness (SE) of cavities modelled with thin boundaries, in the Finite-Difference Time-Domain (FDTD) method, are examined. The errors in SE are found to be associated with the error in the surface area of the cavity caused by the use of a stair-cased mesh. An empirical solution is demonstrated, which improves the stair-cased model accuracy to be comparable to that achievable by a conformal model. Errors in the resonant frequencies, Q factors and field minima of a cavity, due to the stair-cased mesh, are also noted.