Effective impedance of a wire grid parallel to the earth´s surface

The reflection of electromagnetic waves from a parallel wire grid, located near the plane interface of two homogeneous media, is considered. The incident wave is polarized such that the magnetic vector is perpendicular to the grid wires. It is shown that, for this particular case, the grid may be represented by a pure shunt element in the equivalent transmission line circuit. The application of the results to the design radial wire ground systems for vertical monopole systems is mentioned.