A conservative FDTD M(2,4) scheme in 3D without time step reduction for reducing dispersion

In this paper, we propose a FDTD(2,4) scheme to reduce numerical dispersion compared to the standard Yee scheme. This scheme is designed to retain a two dimensional stencil in the field update equations. We derive the numerical dispersion equation of this scheme and show its high-phase accuracy at low-grid resolutions. Moreover, the Courant-Friedrichs-Lewy condition (CFL) of this scheme does not decrease the usual standard time-step given by the CFL condition of the Yee scheme. With this scheme, we can model large structures with high accuracy results.