A Fundamental LOD-FDTD Method in Cylindrical Coordinates

An efficient implicit finite-difference time-domain (FDTD) algorithm in cylindrical coordinates is developed on the basis of a fundamental locally 1-D scheme. The Sherman-Morrison formula is introduced to treat a cyclic matrix and the image theory is utilized to impose the perfect electric conductor boundary condition. The effectiveness of the present method is investigated through the analysis of a metal disc-type terahertz surface wave splitter. The computation time is found to be reduced to less than half that of the explicit FDTD method, while maintaining a comparable accuracy.