Electromagnetic Field Computation Using Space-Time Grid and Finite Integration Method

A finite integration (FI) method on a space-time grid is studied for computation of electromagnetic wave propagation, where a nonuniform time-step distribution is naturally introduced. Orthogonality between dual grids is given by the Lorentz metric to obtain a constitutive equation for electromagnetic variables. Electromagnetic field computations show that the FI method on a nonuniform space-time grid yields correct wave propagation.