A CP-FDTD Preprocessor in Cartesian and Rectangular Coordinates

Abstract

In. this paper we present a versatile mesh generator in Cartesian and Rectangular co-ordinates for the Contour path Finite Difference Time Domain method wherein the grid is adjusted locally, to follow the contour of the geometric boundaries. The information about geometry, curved interfaces (dielectric/dielectric, PEC/air etc) material parameters, angles are obtained from the geometry of the intersecting interfaces at the mesh stage itself and does not need any particular area calculation for implementation at the FDTD solver stage. When run on a stair stepped or o contour path FDTD solver, the conformal approximation permits modeling of sloped and curved boundaries, while the stepped approximation permits modeling of linear material media. Additionally, to model thin layers smaller than the spatiaL step size a local sub girding approach that aLlows fine geometries to be modeled is used at the mesh stage itseLf. This means structures that are less than the grid discretization such as thin plates and small bumps are incorporated into the mesh at negligibLe costs.