Efficient and Accurate Modeling of Curved Dispersive Objects Using FDTD With Special Anisotropic Treatment

While much research has been done on the use of finite-difference time-domain to analyze structures containing dispersive material and curved dielectric structures, there is still a need for an efficient method to treat the general case of curved boundaries between dispersive anisotropic materials. In this paper, the state-of-the-art is extended by combining the auxiliary differential equation method for dispersive material with the use of dielectric smoothing for curved boundaries to allow efficient and accurate solutions for structures containing these sorts of boundary. The effectiveness of the method is demonstrated by means of the example of scattering from a spherical water droplet having Debye properties and the behavior of a spherical cloaking structure consisting of a material having anisotropic, space-dependent Drude properties. In each case improvement over standard techniques is shown.