An efficient PSTD algorithm for cylindrical coordinates

A pseudospectral time-domain (PSTD) algorithm is developed to overcome limitations in the conventional solution methods for Maxwell's equations in cylindrical coordinates. It is based on the fast Fourier transform (FFT) representation of spatial derivatives and a centered grid. The main contributions of this algorithm are to eliminate the singularity problem at the axis and to allow a larger time step. It uses a coarse grid close to the Nyquist sampling density provided that the geometrical modeling does not require fine cells. It reduces the required number of unknowns and the number of time steps in the finite-difference time-domain (FDTD) method and is efficient for large-scale problems.