Numerical Examinations of the Stability of FDTD Subgridding Schemes

Abstract : The stability of two-dimensional Finite-Difference Time-Domain subgridding schemes was numerically examined. Both the same-time-step and the multiple-time-step schemes were considered. Results show that the multiple-time-step subgridding scheme is late-time unstable due to larger-than-unity eigenvalues. As to the same-time-step subgridding schemes, stability is related to the treatment of comer regions.