Patent ID: 7868818

Claim:
An antenna, comprising a plurality of top-loaded monopole antenna elements mounted above a ground plane for providing coverage over a predetermined range of angles in azimuth using a plurality of beams, each antenna element having a base section and a top section, wherein a feed conductor extends from an entry point provided in the base section to connect to a top element positioned at the top section, and the feed conductor is surrounded by and insulated from a hollow cylindrical electrically conducting stem section that extends from the base section, where the stem section connects to the ground plane, to a level proximate to but separated from the top element, in combination with a switch array, wherein at least some of said plurality of antenna elements are connected to switches in said switch array and wherein said switch array is operable to connect selected pairs of said antenna elements to a signal path to thereby generate each of said plurality of beams and to establish a virtual short circuit in respect of unselected antenna elements.