H. Shi et Jl. Drewniak, DISPERSION COMPARISON FOR DSI-BASED AND TENSOR-BASED NONORTHOGONAL FDTD, IEEE microwave and guided wave letters, 6(5), 1996, pp. 193-195
An explicit formulation of the finite-difference time-domain-discrete
surface integral (FDTD-DSI) technique has allowed a rigorous study of
numerical dispersion for the method. The study shows that the DSI- and
tensor-based FDTD methods do not have the same numerical dispersion r
elation. It also clarifies the recently reported discrepancies in the
dispersion relation between the two approaches. This study also shows
that the tensor-based FDTD algorithm exhibits better dispersion proper
ties for a two-dimensional uniformly skewed mesh.