A generalized local time-step scheme for the FVTD method for efficient simulation of microwave antennas

This paper introduces a new generalized local time-step scheme to improve the computational efficiency of the Finite-Volume Time-Domain (FVTD) method. The new approach exploits the advantages of the FVTD method to use unstructured meshes (which allow inhomogeneity of cell densities) for large electromagnetic circuits with fine structural details and at the same time avoids the disadvantage of using a single time step determined by the smallest cell dimensions in the entire mesh. To illustrate this new scheme a large double-ridged horn antenna excited by a finely resolved coaxial feed is analyzed demonstrating a significant speed-up of the computation.