Numerical computation of corner diffraction coefficients for a plane angular sector

Abstract

Numerical diffraction coefficients are derived for currents associated with vertex diffraction on an infinitely-thin, perfectly conducting semi-infinite plane angular sector. The vertex-diffracted currents are formulated as the difference between the exact and PTD currents. The difference current is expressed as a traveling wave originating from the tip of the plane angular sector with unknown amplitude and decay factors. The unknown factors are then calculated by using least squares fit approximation. The discontinuities of the current density along the shadow boundaries are removed by the inclusion of the vertex-diffracted currents. The resulting current density also behaves as suggested by the edge condition. It is also demonstrated that incorporation of the vertex-diffracted currents improves the accuracy of the RCS pattern.