THE NEAR-FIELD OF A WIRE GRID MODEL

The extreme near-field behavior of the wire grid model of a conducting surface is examined. Using a wire grid model of an infinite transverse magnetic (TM) circular cylinder, it is verified that the best accuracy for the E-field is obtained when the wire satisfies the "same surface area" rule of thumb. Two excitations are considered: 1) a uniform surface current and 2) plane wave incidence. In case 1), although the boundary value match between the wires is poor, the extreme near field is still quite accurate. In case 2), the near field is also accurate, however, the largest errors occur not between the wires, but in the interior of the scatterer. In both cases, the boundary match between the wires as a check on the accuracy of the solution is misleading.