FDTD modeling of arrays and grids of lossy conductors based on impedance sheet conditions

Fast finite-difference time-domain (FDTD) modeling techniques for arrays of parallel wires and wire meshes are developed. The analytical basis of the models lies in the use of impedance sheet conditions (Kontorovich conditions) for dense wire arrays and grids, connecting the tangential electric fields and the averaged currents in the plane of a wire array or grid. The proposed methods allow us to avoid the direct discretization of the fields inside the wires, greatly simplifying the modeling task. The conductor losses in the wires are accounted for assuming a strong or weak skin effect. The impedance sheet conditions are formulated in the time-domain using the convolution integral, which is evaluated recursively in FDTD. Numerical examples and comparisons with analytical results are provided to verify the proposed techniques.