Modified edge representation method in diffraction with higher order correction

Abstract

Physical Optics (PO) which is one of the high frequency asymptotic techniques and is widely used for the diffraction analysis. In PO theory, the currents generated on the illuminated side of the scatterer are integrated over the surface to give the scattered field. The field generated from the scatterer is the main topic in the electromagnetics. The Modified Edge Representation (MER) is an expression of line integration for computing the scattered and diffracted field reduced from PO. The MER itself is one of concepts to define the equivalent edge currents (EECs) for line integration expression of PO; the surface-to-line integral reduction is important not only for reducing the computational load but also for extracting the mechanism of the field and relieving the difficulties in ray theories such as Geometrical Theory of Diffraction (GTD) and Uniform Geometrical Theory of Diffraction (UTD). According to the method of stationary phase, the surface radiation integral could be asymptotically decomposed into two leading components, the first one GO reflection component is emanating from the stationary phase point (SPP) in the integration area and the second diffraction component expressed in terms of line integration of EECs along the edge of the scatterer.