Generalized expressions of equivalent edge crrrents for physical optics

fringe diffraction and total fields are derived eccording to the concept of the method of equivalent edge currents

and they can be re duced to those exprossions published.An optimum expression of equivalent edge currents for PO field is ob tained.The first

second and third order equivalent edge currents are derived based on the exact expression of non-uniform currents for a half-plane.Bistatic RCS of rhombic flat plat are calculated by the method presented in the paper

which is in good agreement with experimental results.