A new interpretation of the integral equation formulation of cylindrical antennas

The validity of the conventional integral equation formulation of cylindrical antennas is often criticized because of an approximation of the kernel of the integral equation. If the antenna is of the form of a cylindrical tube there is an exact integral equation formulation. By means of the variational technique the integral equation for the cylindrical tube can be solved approximately. When the length of the tube is large compared to its diameters the input impedance of the structure is found to be the same as if one had used the approximate integral equation at the very beginning of the analysis. This new procedure therefore clarifies one main ambiguity involved in the early works of the theory of cylindrical antennas based upon the approximate integral equation. It also enables us to treat the problem of relatively thick cylindrical antennas.