A fourth-order accurate FDTD scheme with long-time stability

This letter presents a new finite-difference time-domain (FDTD) scheme with fourth-order accuracy in time and space. A combination of staggered backward differentiation time integrator and high-order spatial discretization is used to derive fourth-order accurate FDTD equations. The fourth-order accuracy of the proposed FDTD method is verified by monitoring L/sub 2/ norm errors in a two-dimensional partially-filled cavity. Furthermore, the computational cost study shows that the proposed fourth-order scheme is much more efficient than Yee's second-order FDTD scheme in solving the inhomogeneous cavity problem.