Patent ID: 8436776

Claim:
A near-horizon antenna structure comprising: an upper radiating element comprising a straight conductive trace disposed on a planar surface of a non-conductive substrate; a rectangular lower radiating element separated from the upper radiating element by a vertical separation distance, and a rectangular conductive region disposed on the planar surface, the rectangular conductive region coupled to the rectangular lower radiating element and protruding from the rectangular lower radiating element, the rectangular lower radiating element serving as a ground plane disposed on the planar surface, wherein the rectangular lower radiating element has a height greater than one-half of a height of the substrate, and the vertical separation distance is no greater than 0.06 wavelengths to provide an antenna pattern having donut-shape over a bandwidth from 2.5 to 3.8 GHz; and a feed point provided between the upper and lower radiating elements; wherein when the planar surface is positioned vertically, far-field effects of current flowing in opposite directions on the upper radiating element cancel and far-field effects of current flowing in opposite directions on the lower radiating element cancel to provide the antenna pattern with increased gain in horizontal directions and reduced gain in vertical directions.