Modification on a Thin-Wire Representation for FDTD Calculations in Nonsquare Grids

We have reviewed three representative techniques, proposed by Umashankar , Noda and Yokoyama, and Railton , to represent a wire having an arbitrary radius in finite-difference time-domain calculations. The technique of Railton can be applied to represent a thin wire in a lossy medium as well as in a lossless medium, even when a nonsquare grid is used. However, the technique yields less accurate results as the ratio in lengths of the longer side of the employed nonsquare cell to the shorter side increases, and it is not practically effective when the ratio is larger than about 4. We have modified the technique of Railton , and shown that the modified technique yields reasonably accurate results when the ratio in lengths of the longer side of the nonsquare cell to the shorter side is smaller than about 8.