The physical optics method was used to study the reduction of radar cross section (RCS) due to variation of the internal angle of a dihedral corner reflector. Singly, doubly, and triply reflected contributions are considered, so the results obtained are valid for all dihedral reflectors with internal angles greater than 60 degree . The reduction, RCS achievable for a given deviation from orthogonality, is dependent on the size of the reflector, in terms of wavelength of the incident radiation. For plate sizes in excess of a few wavelengths, very significant reductions in backscattered RCS can result from quite modest deviations from orthogonality. Nonorthogonality introduces deep interference nulls that are a function of plate size and the deviation angle into RCS patterns of these reflectors. It is shown that a small deviation angle in a reflector can meet the conditions for a interference null along the axis of symmetry.
