Equivalent edge currents of physical optics components for flat plate

The authors propose a novel and heuristic concept for surface to edge integral reduction of physical optics currents in order to obtain PO-EECs (physical-optics equivalent edge currents) without false singularities. Firstly, the edge of the scatterer is divided into segments, each of which is replaced with a fictitious one satisfying the diffraction law at each point. Secondly, classical PO diffraction coefficients are applied to the fictitious edge, and the EECs with only the true singularities are derived. The remarkable accuracy of PO-EEC is demonstrated numerically for dipole-wave diffraction from a flat disk and a square plate. It is noteworthy that the residual current singularity at shadow/reflection boundaries can also be suppressed arbitrarily by taking the limit in the subsequent line integration; uniform PO fields are predicted everywhere.<>