DIFFRACTION AT A THICK SCREEN INCLUDING CORRUGATIONS ON THE TOP FACE

A closed-form high-frequency solution is presented for the near-field scattering by a thick screen illuminated by a line source at a finite distance, This solution is applicable to a thick screen with perfectly conducting side walls and either perfectly conducting or artificially soft boundary conditions on the face joining the two wedges, This lat ter condition is obtained in practice by etching on that face quarter of a wavelength deep corrugations with a small periodicity with respec t to the wavelength, It is shown that the artificially soft surface pr ovides a strong shadowing for both polarizations; thus, it is suggeste d that such configurations may usefully be employed to obtain an effec tive shielding from undesired interferences, Several numerical calcula tions have been carried out and compared with those from a method of m oments (MoM) solution for testing the accuracy of our formulation, as well as to demonstrate the effectiveness of the corrugations in shield ing arbitrarily polarized incident field.