Partially prism-gridded FDTD analysis for layered structures of transversely curved boundary

In this paper, a partially prism-gridded finite-difference time-domain (FDT D) method is proposed for the analysis of practical microwave and millimete r-wave planar circuits. The method is featured by hybridizing the flexible prism-based finite-element method to handle the region near the curved meta llization boundary and the efficient rectangular-gridded FDTD method for mo st of the regular region. It can be used to deal with shielded or unshielde d planar components such as patch antennas, filters, resonators, couplers, dividers, vias, and various transitions between planar transmission lines, Although only representative structures, e.g., grounded via, through hole v ia, and coplanar waveguide to coplanar stripline transition, are analyzed i n this paper, the underlined formulation is applicable to layered structure s with arbitrary curved boundary in transverse direction, The accuracy of t his method is verified by comparing the calculated results with those by ot her methods. Also, by the analysis of computational complexity, the present method is shown to be as efficient as the conventional FDTD method, with n egligible overhead in memory and computation time for handling the curved b oundary.