The universal current distribution near the end of a tubular antenna

An asymptotic solution for the charge density and current near the end of a linear tubular antenna is obtained by means of the Wiener–Hopf technique. It is found that, due to the charge-repulsion effect, the distributions of charge per unit length and of current within a distance of the order of the radius from the end are significantly different from the sinusoidal distributions that are the solutions from approximate theories. Furthermore, the relative distributions are independent of the length of the antenna and of the frequency of operation.