Diffraction by plane screens

A new approach is proposed to address the problem of the diffraction of a spherical incident wave by soft or hard plane screens of arbitrary shape at high frequencies. The theoretical formalism is based upon the matched asymptotic expansions method and the analysis is restricted to single diffraction at the edge of the screen. It is shown that the inner solution which is valid near the edge can be approximated by the solution of the diffraction by a half‐plane while far from the edge, the outer solution may be built up as the sum of two components: One is the physical optics solution and the other is the sum of two edge integral solutions. These last solutions are an extension of the solution which has been used to describe the acoustics of the slender bodies and their calculations are considerably simplified when the incident angle is perpendicular to the edge. It is proved that the present results are asymptotically equivalent to the geometrical theory of diffraction and the physical theory of diffracti...