Abstract: An antenna system includes a reflector having a focal point, and a phased array having feed elements. Each feed element is disposed a same distance from the focal point of the reflector. A method for varying the beamwidth of an antenna system includes providing the antenna system with a reflector having a focal point and feed elements disposed a same distance from the focal point. The feed elements includes one or more inner feed elements and one or more outer feed elements. The method further includes adjusting relative amplitudes of the inner feed elements and the outer feed elements to adjust the beamwidth of the antenna system. An antenna system includes a parabolic reflector having a focal point, and a phased array having one or more inner feed elements and one or more outer feed elements. Each of the feed elements is disposed a same distance in wavelengths from the focal point, and is oriented towards the focal point.

Abstract: A UWB flat antenna apparatus is disclosed. The UWB flat antenna apparatus includes an antenna element pattern, a ground pattern, and a multiple-stage filter including plural filter elements. Therein, the filter elements are electrically connected in series and are stacked, and the multiple-stage filter and the ground pattern are stacked.