An efficient PSTD algorithm for cylindrical coordinates

A pseudospectral time-domain (PSTD) algorithm is developed to overcome limi tations in the conventional solution methods for Maxwell's equations in cyl indrical coordinates. It is based on the fast Fourier transform (FFT) repre sentation of spatial derivatives and a centered grid. The main contribution s of this algorithm are to eliminate the singularity problem at the axis an d to allow a larger time step. It uses a coarse grid close to the Nyquist s ampling density provided that the geometrical modeling does not require fin e 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 f or large-scale problems.