A TF/SF Plane Wave Source Condition for the Constraint-Preserving FVTD Method

A low-leakage total-field/scattered-field plane wave source condition capable of propagating at any incident angle is developed for a newly-developed DGTD-based FVTD method. This constraint-preserving FVTD method provides solutions up to any order of accuracy, preserves the divergence constraints imposed by Gauss’ laws, and may be easily adapted to non-conformal and unstructured meshes. In order to implement the proposed plane wave source condition, several of the steps within the updating loop of the FVTD model, including the Riemann solvers and update equations, must be adapted to ensure the field variables always remain consistent (are consistently designated as either total or scattered fields). The proposed total-field/scattered-field technique is shown to provide numerical leakage errors at the level of machine precision (−300 dB) for second-, third-, and fourth-order constraint-preserving FVTD schemes.