Subcell FDTD modeling of electrically thin dispersive layers using Z transforms

A novel technique for treating electrically thin dispersive layers with the finite-difference time-domain (FDTD) method based on Z transforms is introduced. The proposed model is based on the subcell technique, where the constitutive relations are locally averaged in the FDTD grid. The most significant feature of the proposed model is its ability to model rather complicated dispersive layers having multiple pole pairs. The model is validated with several numerical examples making comparison with the exact results