An Elliptical Cylindrical FDTD Algorithm for Modeling Conformal Patch Antenna

An explicit finite-difference time-domain (FDTD) method is described using a uniform elliptical cylindrical spatial grid for time-domain Maxwell's equations to accurately and efficiently model conformal elliptical cylindrical line-fed patch antennas and overcome stair-casing errors. Such errors are encountered when a Cartesian spatial grid is used for modeling curved surfaces. In addition, the method described in this paper obviates coding complexity encountered in modeling of curved surfaces which is manifest using CP-FDTD or CFDTD techniques. Characterizing expressions representing the absorbing boundary condition and Courant stability condition are presented and used to provide a highly effective algorithm to simulate conformal microstrip antennas. The proposed FDTD algorithm is validated against HFSS results showing excellent correlation.