The Beverage wave antenna: Radiation field patterns
Abstract
This report presents the results of a theoretical and experimental investigation of the transmitting and receiving properties (farfield radiation patterns) of horizontalwire antennas placed over an imperfectly conducting halfspace. Particular emphasis is given to the Beverage Wave Antenna, a special type of horizontalwire antenna placed in close proximity to the earth. Early work by Sommerfeld showed that the radiation from a dipole above an imperfect earth could be separated into a space wave (which could reflect off the ionosphere and which predominates at large distances above the earth) and a surface wave (which could diffract around the curvature of the earth and which dominates close to the surface). Because of the difficulties involved in solving the Sommerfeld integral formulation, asymptotic approximations valid in the radiation zone have generally been employed to solve this problem. The useful approximate forms developed earlier by Norton have been used in this study, the only difference being that in the present analysis the exact expressions for the antenna current are used rather than an assumed current distribution. An expression for the spacewave radiation pattern is formulated using a 'geometric optics' approximation, while the superposition principle is used to sum the fields of individual infinitesimal dipoles to obtain the surfacewave radiation pattern. Expressions for a number of useful antenna parameters (efficiency, fronttoback ratio, antenna gain, effective length) are then derived.
 Publication:

NASA STI/Recon Technical Report N
 Pub Date:
 February 1977
 Bibcode:
 1977STIN...7729354S
 Keywords:

 Antenna Radiation Patterns;
 Dipole Antennas;
 Surface Waves;
 Wave Diffraction;
 Diffraction Propagation;
 Far Fields;
 Ionospheric Propagation;
 Sky Waves;
 Communications and Radar