A New Perspective on the Cylindrical Antenna Theory

Abstract

This paper presents a new perspective on the analysis of the cylindrical antenna theory. It applies the cylindrical surface waves on an infinitely long cylindrical conductor, which are similar to the Sommerfeld axial cylindrical surface waves, to describe the conventional postulate of applying a sinusoidal current distribution on a cylindrical dipole antenna. This treatment leads to the derivation of simple expression for the current on a cylindrical dipole antenna of finite conductivity, which is in good agreement with the current obtained from the three-term approximations. Also, it proposes an expression for the current on an infinitely long cylindrical dipole antenna of finite conductivity, which is also in good agreement to the current found from applying the Fourier transform technique. Moreover, this paper shows that the complex propagation constant used in the three-term approximation is similar to the complex propagation constant of the principal Sommerfeld wave on the surface of an infinitely long cylindrical conductor. Therefore, a more accurate representation of the current near the feeding point is proposed based on the complex propagation constants of multiple Sommerfeld waves.