Azimuth array of rotory antennas with selectable lobe patterns

Abstract

A radio transmission antenna system and method of transmitting radio signals. The antenna system includes an array of separately rotatable directional antennas which are spaced along an azimuth line. The antennas are rotated to direct their respective major lopes of transmitted rf energy along parallel lines in a selected direction relative to the azimuth line. Two separate adjustments are made to the phase of identical rf signals which are fed to each antenna in the array. A first phase adjustment is made when required to produce a coherent wave-front transmitted in the selected direction. This first phase adjustment shifts the phase of the signals fed to adjacent antennas in the array by 180.degree.. This adjustment establishes a radiation pattern in any given azimuth quadrant which records major lobes, established by rotating the antennas, at 0.degree. and 90.degree. relative to the azimuth line and at least one intermediate angle between 0.degree. and 90.degree.. The second adjustment changes the phase of the signals fed to antennas which are spaced equally from the geographic center of the array by equal, opposite magnitudes. This second adjustment electrically wobbles the direction of the major lobe on either side of the direction established by the first adjustment. A method of operating the above-described array includes the steps comprising the spacing and phase adjustments described above.