Trw Limited

Hughes Aircraft Company

Northrop Grumman Systems Corporation

Ann L Peebles

Charles W Chandler

Mon N Wong

Stuart T Linsky

Alan Cherrette

George H Simkins

Gregory P Junker

Louis C Wilson

A side-fed dual reflector antenna system () of the present invention overcomes the size cost and complexity limitations associated with conventional single and multiple reflector antenna systems. The antenna system () includes a feed array () including separate feeds for generating separate respective antenna beams, a subreflector () for reflecting the separate respective antenna beams generated by the separate feeds of the feed array (), and a reflector () having a shaped reflecting surface for reflecting the separate respective antenna beams received from the subreflector () toward a terrestrial target () to produce substantially contiguous flat beams, each of which provides substantially uniform coverage within a predetermined coverage area on the terrestrial target. The subreflector () and each of the separate feeds in the feed array () are arranged so that a center of each of the separate respective antenna beams illuminates a center of the reflector () subsequent to being reflected from the subreflector ().

Multi-beam antenna system with shaped reflector for generating flat beams

An antenna system comprising a feed array, a subreflector and a main reflector which are oriented to define a offset gregorian antenna geometry. The feed array is comprised of a plurality of separate feeds which are aligned on a predetermined contour. Each feed array is coupled to a feed network which acts to combine the illumination beams of clusters of a preselected number of feeds to produce a plurality of composite illumination beams. Each composite illumination beam is directed to be incident upon a separate predetermined location on the subreflector which directs the composite illumination beams and directed towards the main reflector. Each composite illumination beam is reflected by the main reflector in a preselected direction so that each composite illumination beam forms an antenna beam that impinges a predetermined coverage area on the Earth. Each antenna beam defines a separate coverage cell in the coverage area, wherein the position and orientation of the feeds, the subreflector and the main reflector provides antenna beams over a full Earth field of view coverage area where each antenna beam is approximately symmetrically shaped.

Compact offset gregorian antenna system for providing adjacent, high gain, antenna beams

An antenna system comprising a feed array, a subreflector and a main reflector which are oriented to define a front-fed dual reflector antenna geometry. The feed array is comprised of a plurality of separate feeds which are aligned in a predetermined contour. Each feed array is coupled to a feed network which acts to combine the illumination beams of clusters of a preselected number of feeds to produce a plurality of composite illumination beams. Each composite illumination beam is directed to be incident upon a separate predetermined location on the subreflector which directs the composite illumination beams towards the main reflector. Each composite illumination beam is reflected by the main reflector in a preselected direction so that each composite illumination beam forms an antenna beam that impinges a predetermined coverage area on the Earth. Each antenna beam defines a separate coverage cell in the coverage area, wherein the position and orientation of the feeds, the subreflector and the main reflector provides antenna beams over a full Earth field of view coverage area where each antenna beam is approximately symmetrically shaped.

Compact front-fed dual reflector antenna system for providing adjacent, high gain antenna beams

An antenna system comprising a feed array, a subreflector and a main reflector which are oriented to define a side-fed dual reflector antenna geometry. The feed array is comprised of a plurality of separate feeds which are aligned on a predetermined contour. Each feed array is coupled to a feed network which acts to combine the illumination beams of clusters of a preselected number of feeds to produce a plurality of composite illumination beams. Each composite illumination beam is directed to be incident upon a separate preselected location on the subreflector which directs the composite illumination beams towards the main reflector. Each composite illumination beam is reflected by the main reflector in a preselected direction so that each composite illumination beam forms an antenna beam that impinges a predetermined coverage area on the Earth. Each antenna beam defines a separate coverage cell in the coverage area, wherein the position and orientation of the feeds, the subreflector and the main reflector provides antenna beams over a full Earth field of view coverage area where each antenna beam is approximately symmetrically shaped.

Compact side-fed dual reflector antenna system for providing adjacent, high gain antenna beams

A multi-mode, multi-step feed horn (10) for a satellite antenna array that includes multiple transition steps (28-34) that provide control of the mode content of the signal, and the generation of substantially equal E-plane and H-plane beamwidths, with low cross-polarization and suppressed sidelobes. In one particular embodiment, two transition steps (32, 34) allow the E-plane to expand and generate the higher order TM.sub.11, propagation mode. The transition steps (32, 34) and a phase section (18) allow the mode content to be oriented relative to each other in the proper phase so that the useful bandwidth is on the order of 10%-15%. Two other transition steps (28, 30) provide impedance matching between a throat section (12) and the mode content transition steps (32, 34) to prevent or minimize reflections.

Multimode, multi-step antenna feed horn

A waveguide switch operable at microwave frequencies is formed of two waveguides of rectangular cross section with a longer wall and a shorter wall, the two waveguides sharing a common shorter wall. Two coupling windows are disposed within the common wall for coupling electromagnetic energy between the two waveguides, each coupling window introducing a 90.degree. phase shift. Each window couples one-half the power of an electromagnetic wave from a first of the guides to a second of the guides. The common wall is parallel to the electric field of the coupled wave, with each wave being a TE wave. A 90.degree. phase shift is introduced by each coupling with the result that utilization of both windows produces a summation of the two waves in the second of the waveguides and a cancellation of the two waves in the first of the waveguides. Gates are employed for selectively closing off either one or both of the windows to retain all of the power in the first waveguide, or to close off only one of the waveguides for an equal distribution of the power in both waveguides.

Growing community of inventors

Santa Monica, CA, United States of America

Ann L Peebles