Scattered Field Fdtd Formulations for Debye Dispersive Media

Astract ---New implementation of scattered field FDTD formulations of dispersive material are employed yielding accurate and mathematically compact procedures. This work is based on the application of the Z-transform on the Debye model representing the dispersion in conjunction with the relation between the electric field and the displacement current. The result is an approximate frequency domain formulation, which can be easily transformed into discrete time domain updating equations. Three approaches are presented. The last one is mathematically compact, easy to use, and can be extended to any number of Debye poles without the need for further mathematical manipulations. Reflection coefficient at the interface between the air and the dispersive medium having more than one pole is computed and compared with the analytical solution.