Reduction of late time instabilities of the finite difference time domain method in curvilinear coordinates

Late time instabilities are always present when applying the FDTD method in general curvilinear coordinates. In this paper, the stability analysis is performed on local nonorthogonal FDTD (LNFDTD) and a novel time-subgridding scheme is developed to reduce instabilities so that the full characteristics of electromagnetic structures can be explored.