Method and apparatus for tri-band feed with pseudo-monopulse tracking

• US 8,537,068 B2
• Filed: 01/26/2010
• Issued: 09/17/2013
• Est. Priority Date: 01/26/2010
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: Martin, Larry C., Chang, Yueh-Chi, Hanlin, John J., Call, William F.
• Primary Examiner(s): LE, HOANGANH T
• Application Number:
  US12/693,494
• Publication Number:
  US 20110181479A1
• Time in Patent Office: 1,330 Days
• Field of Search: 343/786, 343/785, 343/772
• US Class Current: 343/786
• CPC Class Codes: H01Q 13/025 Multimode horn antennas; Horns using higher mode of propagation H01Q13/0241 takes precedence; multiple beam H01Q25/04
• CPC Class Codes: H01Q 19/08 for modifying the radiation pattern of a radiating horn in which it is located corrugated horns H01Q13/0208; producing a circular polarisation H01Q13/0241
• 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 21/28 Combinations of substantially independent non-interacting antenna units or systems multiple beam H01Q25/00
• CPC Class Codes: H01Q 25/02 providing sum and difference patterns H01Q25/04 takes precedence
• CPC Class Codes: H01Q 5/47 with a coaxial arrangement of the feeds

Abstract

Methods and apparatus for a feed assembly for a reflector antenna including an aperture common to low, mid, and high frequency bands, a polyrod design to launch signals in the mid and high frequency bands, a horn to launch signals in the low frequency band, a co-located phase center for launching signals in the low, mid, and high frequency bands, and a low-band monopulse array located on a surface about the aperture to track a satellite.

Claims

1. A feed assembly for a reflector antenna, comprising:

an antenna aperture common to low, mid, and high frequency bands;

a polyrod to launch signals from the aperture in the mid and high frequency bands while supporting the low band;

a horn to launch signals from the aperture in the low frequency band;

a co-located phase center for launching signals in the low, mid, and high frequency bands; and

a low-band monopulse array located on a surface about a perimeter of the aperture to track a satellite.

2. The feed assembly according to claim 1, wherein respective beamwidths for the low, mid, and high frequency bands is approximately equal.

3. The feed assembly according to claim 2, wherein the respective beamwidths are about 10 dB.

4. The feed assembly according to claim 1, wherein the monopulse array includes a four patch antenna array.

5. The feed assembly according to claim 1, wherein a waveguide network for the low frequency band is elongated to minimize blockage of the reflector antenna.

6. The feed assembly according to claim 1, wherein a length of a polarizer for the mid and high frequency bands is reduced to minimize blockage of the reflector antenna.

7. The feed assembly according to claim 1, wherein a length of a feed is less than six inches.

8. The feed assembly according to claim 1, wherein a diameter of the aperture is less than 2.5 inches.

9. The feed assembly according to claim 1, wherein the monopulse array is implemented in a single stripline layer.

10. The feed assembly according to claim 1, wherein the monopulse array provides sum, delta azimuth, and delta elevation beams in a downlink band and a single beam in an uplink band.

11. The feed assembly according to claim 1, further including a turnstile junction coupled to the horn for coupling low-band energy to four symmetric waveguide channels.

12. A method, comprising:

receiving and transmitting signals using a feed assembly for a reflector antenna having an antenna aperture common to low, mid, and high frequency bands;

employing a polyrod to launch signals from the aperture in the mid and high frequency bands while supporting the low band and employing a compact horn to launch signals from the aperture in the low frequency band, wherein a phase center for launching signals in the low, mid, and high frequency bands is co-located; and

employing a low-band monopulse array located on a surface about a perimeter of the aperture to track a satellite.

13. The method according to claim 12, further including employing respective beamwidths for the low, mid, and high frequency bands that are approximately equal.

14. The method according to claim 13, wherein the respective beamwidths are about 10 dB.

15. The method according to claim 13, wherein the monopulse array includes a four patch antenna array.

16. The method according to claim 13, further including elongating a waveguide network for the low frequency band to minimize blockage of the reflector antenna.

17. The method according to claim 13, further including reducing a length of a polarizer for the mid and high frequency bands to minimize blockage of the reflector antenna.

18. The method according to claim 13, wherein a length of a feed is less than six inches.

19. The method according to claim 13, wherein a diameter of the aperture is less than 2.5 inches.

20. The method according to claim 13, further including implementing the monopulse array in a single stripline layer.