Simple edge basis functions for open-ended bodies of revolution

A relatively simple and widely-used basis function in the method of moments solution for surface currents on a conducting scatterer is the piecewise linear function (triangle function). However, the triangle function does not exhibit the proper edge behavior for surface current and charge at a conducting knife-edge. The proper edge behavior is incorporated into the basis function set via a minor modification. The effect of the modified basis set on the computation of the axial electric field in the aperture of open-ended bodies of revolution is considered. Both straight and tapered cylinders are investigated. The convergence properties of the edge-modified triangle basis set are found to be superior to those of the normal triangle basis function set.