A Critical Study of Two Broadcast Antennas

A theoretical study is made of a double doublet, determining the vertical radiation characteristics for various current ratios. Also, the horizontal field intensity is plotted as a function of the current ratio and phase angle. Three experimental designs are discussed. Fading measurements show the improvement of the upper doublet in comparison with a quarter-wave antenna. A theoretical study is made of a loaded quarter-wave antenna showing vertical radiation characteristics and horizontal field intensity as a function of the current distribution. Recording measurements verify that fading at a distance is materially reduced when the antenna is properly loaded.