FDTD-Compatible Green's function based on scalar discrete Green's function and multidimensional Z-transform

In this contribution, a new formulation of the discrete Green's function (DGF) is presented for the finitedifference time-domain (FDTD) grid. Recently, dyadic DGF has been derived from the impulse response of the discretized scalar wave equation (i.e., scalar DGF) with the use of the multidimensional Z-transform. Its software implementation is straightforward because only elementary functions are involved and a single function requires computations in the multipleprecision arithmetic. Since the proposed formulation is based on scalar DGF, it allows to estimate steady-state values of dyadic DGF with the use of the windowing technique applied to scalar DGF. Applications of the proposed DGF formulation are demonstrated in basic simulation scenarios facilitated by the time-domain diakoptics approach.