A new way to extend the finite difference time domain (FDTD) technique to nonorthogonal grids is described in this paper. The method, whose theoretical foundations are based on the Finite Integration Technique and on recently extended affine theories, can be proven to be both stable and consistent. In order to show its benefits, the nonorthogonal FDTD is applied to the analysis of a cylindrical cavity and to the characterization of biconical antennas for ultrawideband applications.
