MODELING DISPERSIVE DIELECTRICS FOR THE 2-D TLM METHOD

The transition line matrix (TLM) method, since it is a time-domain met hod, cannot deal directly with dispersive media. We propose a way for modeling such media, starting from the causality relationship between field vectors D and E, which is discretized over the same space-time m esh as the two-dimensional TLM mesh, This leads to adding a voltage so urce at each node, its value depending on the previous instants, The m ethod is validated by computing the reflection coefficient at an air-w ater interface and the cutoff frequencies of a rectangular waveguide c ontaining a Debye dielectric.