A staggered time integration technique for spectral methods [computational electromagnetics]

The spectral methods on unstructured grids developed in recent years provide a flexible, accurate and efficient tool to model large-scale broadband electromagnetic problems with complex geometry. In this paper, a staggered-time integrator is introduced in the spectral methods to further improve their computational efficiency. A method similar to predictor and corrector methods are used in the staggered time integration technique to overcome the difficulty of the staggering of the boundary penalty term. Compared with other 2nd-order time integration methods, it requires less memory and CPU time. Thus it is especially suitable for lower-order spectral methods. Case studies of the radiation of an electric dipole source in a cylinder validate the technique. Applications in the modeling of photonic bandgap materials are shown to confirm the efficacy of the method.