Higher order equivalent edge currents for fringe wave radar scattering by perfectly conducting polygonal plates

An approach for including higher order edge diffraction in the equivalent edge current (EEC) method is proposed. This approach, which applies to monostatic as well as bistatic radar configurations with perfectly conducting polygonal plates, involves three distinct sets of EECs. All of these sets of EECs contain very few singularity problems. In order to obtain an approximation to the scattered field, the three sets are added and integrated along the circumference of the scatterer. This procedure is straightfoward, and since most singularity problems have been eliminated, it is numerically well behaved. The approach is applied to a configuration involving a square plate. Substantial improvements were achieved. The calculations also illustrate that the edge interaction can be significant, although the direction of incidence is far from the plane of the scatterer