Stability Considerations for the Direct FDTD Implementation of the Dispersive Quadratic Complex Rational Function Models

In this communication, detailed stability considerations for the direct finite difference time domain implementation of the dispersive quadratic complex rational function models are investigated. It is shown that the time step stability limit of this numerical scheme is more restrictive than the previously published constrain. In addition, it is found that by using high spatial resolution, the stability limit tends to retain the classical Courant-Friedrichs-Lewy constrain. Numerical examples are included to verify these results.