Grid design benchmark on sheets with nonzero thickness

Abstract

The conventional scattering analysis of perfectly conducting sheets ignores the scattering contribution of the rim. The so-called thin-surface scheme arises from the discretization of the Electric-field Integral Equation by assuming the sheet thickness to be null. This gives rise to many less unknowns than the full approach, arising from modelling the whole plate. Although good accuracy is observed in many practical applications, the thin-plate scattering analysis of thick enough sheets, especially under oblique incidences, with low grazing angles, exhibits great inaccuracies. A recent approach, so-called thick-surface, has proved to show similar accuracy as the full scheme, also in those cases where the thin-surface scheme fails, with moderate computational effort. In this paper, we show RCS results computed with the thick-surface approach for several sheets with nonzero thickness where the thin-surface scheme fails. Several types of meshes are adopted, triangular, quadrangular or hybrid. The required symmetries for the generation of the meshes are pointed out in each case.