Admittance of a dipole antenna driven by a two-wire line

A new theoretical approach to the problem of the symmetric dipole antenna, driven by a two-wire line, is presented. The dipole and the line are treated as a unique boundary-value problem, and, as a consequence, a new, conveniently defined, apparent driving-point admittance is introduced. The analysis of the problem leads to a system of two integral equations with the dipole and line currents as unknown subintegral functions. The integral equations are solved approximately by using the so-called point-matching method. The current on the dipole is approximated by a polynomial with unknown coefficients and that on the line by a sum of incident and reflected travelling waves and a polynomial decreasing rapidly with the distance from the end of the line. Theoretical results, obtained by the present theory, reveal a strong dependence of the admittance on the distance between the line conductors. Excellent agreement between the theoretical and available experimental results is found.