Abstract: A broadband corrugated feed horn and flat top multiple beam antenna for use in satellite communication systems, and the like. The profile of corrugations of the horn is specially tuned or designed to flatten the aperture field distribution. As a result, the aperture efficiency increases, and the gain of the corrugated horn also increases. Also, the circular aperture and corrugated construction of the horn result in improved circular polarization characteristics. The flat top multiple beam antenna comprises an oversized reflector and a plurality of high efficiency feed horns that exhibit a flat top aperture field. The present high efficiency corrugated feed horns may be used in the flat top multiple beam antenna. The flat top multiple beam antenna has a reduced interference signal level, increased gain in the coverage area, and improved frequency reusability from a four-color to three-color configuration.

Abstract: Variable beamwidth antenna systems for use on spacecraft that is capable of changing their beamwidths while the spacecraft in on orbit. The variable beamwidth antenna systems include a main reflector, a subreflector, a feed horn, a main reflector displacement mechanism and a feed horn (or subreflector) displacement mechanism. For broaden the beamwidth, the RF feed horn and the subreflector are moved close together by proper distance. The main reflector is moved away from the subreflector along a line through centers of their respective surface by a distance given by a predetermined equation. Another embodiment of the present invention provides for a zoom contour beam antenna system that radiates a contour beam and whose beam is variable or zoomable.

Abstract: A shaped reflector antenna system for use on a communication satellite that comprises a plurality of shaped reflector antenna configurations. In an exemplary system, a first one of the antenna configurations is a diverged shaped reflector antenna and a second one of the antenna configurations is a converged shaped reflector antenna. Each of the shaped reflector antennas comprise a main reflector, a subreflector, and a feed horn. The feed horn illuminates the subreflector with RF energy in the shape of a feed cone that is reflected to the main reflector. The direction of RF energy propagation emitted by each of the shaped reflector antennas is in a direction that is different from a direction defined by a vector between a predetermined vertex and focal point associated with the respective shaped reflector antenna.

Abstract: Variable beamwidth antenna systems for use on spacecraft that is capable of changing their beamwidths while the spacecraft in on orbit. The variable beamwidth antenna systems include a main reflector, a subreflector, a feed horn, a main reflector displacement mechanism and a feed horn (or subreflector) displacement mechanism. For broaden the beamwidth, the RF feed horn and the subreflector are moved close together by proper distance. The main reflector is moved away from the subreflector along a line through centers of their respective surface by a distance given by a predetermined equation. Another embodiment of the present invention provides for a zoom contour beam antenna system that radiates a contour beam and whose beam is variable or zoomable.

Abstract: A Gregorian reflector antenna system optimized for an elliptical antenna aperture. The Gregorian reflector antenna system comprises a main reflector, a subreflector, and a feed horn for illuminating the subreflector. The subreflector illuminates the main reflector with an elliptically shaped feed cone of energy. The subreflector has a surface defined by the equation x 2 a 2 + y 2 b 2 + z 2 c 2 = 1 , where x, y, and z are three axes of the Cartesian coordinate system.

Abstract: Variable beamwidth antenna systems for use on spacecraft that is capable of changing their beamwidths while the spacecraft in on orbit. The variable beamwidth antenna systems include a main reflector, a subreflector, a feed horn, a main reflector displacement mechanism and a feed horn (or subreflector) displacement mechanism. For broaden the beamwidth, the RF feed horn and the subreflector are moved close together by proper distance. The main reflector is moved away from the subreflector along a line through centers of their respective surface by a distance given by a predetermined equation.

Abstract: Improved active multiple beam antennas that comprise an amplifier array or grid amplifier having substantially identical amplifiers. A feed array having a plurality of antenna elements provides RF energy. A microwave lens is disposed adjacent to the feed array that weakly focuses the RF energy from the feed array. The amplifier array or grid amplifier is disposed opposite the microwave lens from the feed array. The feed array illuminates the amplifier array or grid amplifier via the microwave lens. The weakly focused RF signals are amplified without changing their respective directions of propagation, which forms powerful multiple beams in the far field.