It is known that the results of incremental length diffraction coefficients (ILDC) (1) and the method of equivalent edge currents (MEC) (2) differ by terms due to the physical optics (PO) current. These PO components become infinite for certain aspects of observation and illumination, by the extraction of the PO contribution from MEC, ILDC, unlike MEC, predicts finite currents for certain directions of observation. However, as already observed by Mitzner (1), ILDC also displays infinities for certain combinations of observation and incidence directions, though the range of singular aspects reduced in comparison with the MEC. Michaeli (3) derived a set of expressions for the fringe current components of equivalent edge currents, those expressions are finite for all aspects of illumination and observation, except for the Ufimtsev singularity. However, for certain non-singular aspects of ILDC expressions, there is a wide divergence between Michaeli's results (3) and Mitzner's results (1).
展开▼
