Common aperture antenna for multiple contoured beams and multiple spot beams

• US 8,315,557 B1
• Filed: 06/25/2010
• Issued: 11/20/2012
• Est. Priority Date: 12/31/2009
• Status: Active Grant

• Current Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Corporation (Martin Marietta Corporation)
• Inventors: Rao, Sudhakar, Wang, Jim, Hsu, Chih-Chien
• Primary Examiner(s): Alam, Fayyaz
• Application Number:
  US12/823,841
• Time in Patent Office: 879 Days
• Field of Search: 455/427, 455/431, 455/12.1, 455/13.3, 343/765, 343/761, 343/772, 343/775, 343/779, 343/776, 343/786
• US Class Current: 455/13.3
• CPC Class Codes: H01Q 1/288 Satellite antennas
• CPC Class Codes: H01Q 19/17 the primary radiating source comprising two or more radiating elements H01Q19/15, H01Q25/00 take precedence
• CPC Class Codes: H01Q 25/007 using two or more primary active elements in the focal region of a focusing device for operation on different wavebands H01Q5/22

Abstract

An antenna assembly includes a reflector having a focal plane, a first feed element located along the focal plane that illuminates the reflector to create a first contour beam at a first frequency and a second feed element located further from the reflector than the first feed element that illuminates the reflector to create a first spot beam at a second frequency, the second frequency being different than the first frequency.

Claims

1. A method of operating an antenna, the method comprising:

providing a reflector configured to support two or more contour beams created by two or more feed elements, the two or more feed elements being located in a focal plane of the reflector;

providing a spot beam feed element;

illuminating the reflector with the spot beam feed element at a plurality of distances;

measuring a phase angle at an aperture of the reflector of multiple signals created by a spot beam at each distance;

determining a spot beam feed element location selected from the plurality of distances that creates a signal having a phase angle that varies within a limit across the aperture; and

locating the spot beam feed element at the spot beam feed element location to generate a spot beam using the reflector configured to support the two or more contour beams.

2. The method of claim 1, further comprising:

locating a spherical cap at the spot beam element location.

3. The method of claim 1, wherein the spot beam feed element provides a signal in a Ka-band, and the one or more feed elements provide signals in a Ku-band.

4. The method of claim 1, wherein locating the spot beam feed element includes affixing the spot beam feed element to a communications deck of a satellite.

5. The method of claim 1, further comprising:

affixing the feed elements to a communications deck of a satellite.

6. The method of claim 1, including spatially isolating at least a portion two or more contour beams in order to provide sufficient copolar isolation among the two or more contour beams so they can re-use identical the first frequency or frequency band.

7. The method of claim 1, further comprising:

configuring multiple spot beams such that they are spatially isolated in order to provide sufficient copolar isolation among them so that they can re-use identical the second frequency or frequency band.