Abstract: A radio frequency antenna system is provided comprising: a radio frequency lens having a parallel plate region and having disposed along opposing peripheral portions thereof a plurality of array ports and a plurality of beam ports, such array ports being coupled to an array of antenna elements arranged to provide a plurality of differently, directed relatively narrow collimated beams of radio frequency energy from a common aperture, each one of such beams being associated with a corresponding one of the plurality of beam ports; and, means for coupling radio frequency energy directly into the parallel plate region to provide, from the common aperture, a relatively broad beam of radio frequency energy.In a preferred embodiment of the invention, a plurality of amplifiers is provided, each one of the amplifiers being coupled between an array port and a corresponding one of the antenna elements.

Abstract: An antenna element is disclosed having a printed circuit parallel plate region with a parabolically shaped reflecting wall and a flared radiating section. The flared radiating section is disposed along an aperture which intersects the axis of the parabola at an acute angle. A microstrip feed formed integrally with the printed circuit parallel plate region is offset from the reflecting wall and is adapted to introduce radio frequency energy at the focal point of such reflecting wall. Load material is disposed adjacent to the focal point to absorb radio frequency energy reflected by the aperture thereby improving the VSWR of the feed. Such arrangement enables close element-to-element spacing in an array, thereby substantially eliminating grating lobes while enabling intermeshing of the elements to provide port and starboard array antennas.