Rotating screen dual reflector antenna

• US 7,576,701 B2
• Filed: 04/02/2007
• Issued: 08/18/2009
• Est. Priority Date: 04/02/2007
• Status: Active Grant

• Current Assignee: Raytheon Company (Rtx Corporation)
• Original Assignee: Raytheon Company (Rtx Corporation)
• Inventors: McGrath, Daniel T., Wu, Kuang-Yu, Fassett, Matthew, McRae, James C.
• Primary Examiner(s): Phan; Tho G
• Application Number:
  US11/695,112
• Publication Number:
  US 20080238790A1
• Time in Patent Office: 869 Days
• Field of Search: 343/754, 343/755, 343/761, 343/756, 343/757, 343/781.R, 343/837
• US Class Current: 343/754
• CPC Class Codes: H01Q 15/23 Combinations of reflecting surfaces with refracting or diffracting devices
• CPC Class Codes: H01Q 19/06 using refracting or diffracting devices, e.g. lens radome H01Q1/42
• CPC Class Codes: H01Q 19/18 having two or more spaced reflecting surfaces H01Q19/20 takes precedence
• CPC Class Codes: H01Q 3/14 for varying the relative position of primary active element and a refracting or diffracting device
• CPC Class Codes: H01Q 3/20 wherein the primary active element is fixed and the reflecting device is movable

Abstract

A system for steering a beam includes a main reflector that receives a signal from a subreflector and reflects the signal in a reflection direction. A prism refracts the signal in a refraction direction. One or more motors adjust a relative orientation between the main reflector and the prism to change a relative orientation between the reflection direction and the refraction direction to steer a beam resulting from the signal.

Claims

1. A system for steering a beam, comprising:

a main reflector having an asymmetrical pattern and operable to;

receive a signal from a subreflector; and

reflect the signal in a reflection direction, the asymmetrical pattern yielding the reflection direction different from a boresight axis;

a prism coupled to the main reflector and operable to;

refract the signal in a refraction direction; and

one or more motors coupled to at least one of the main reflector or the prism, and operable to;

adjust a relative orientation between the main reflector and the prism to change a relative orientation between the reflection direction and the refraction direction to steer a beam resulting from the signal.

2. The system of claim 1, wherein:

at least one of the main reflector or the prism is operable to rotate substantially about a boresight axis; and

the one or more motors are operable to adjust the relative orientation between the main reflector and the prism by;

rotating the at least one of the main reflector or the prism about the boresight axis.

3. The system of claim 1, wherein the main reflector has a pattern comprising:

a plurality of linear dipole elements; and

a plurality of crossed dipole elements.

4. The system of claim 1, wherein the prism comprises:

a plurality of zone steps; and

an anti-reflective layer operable to reduce reflection of the signal from the prism.

5. The system of claim 1, wherein the one or more motors comprises at least one of:

a prism motor operable to move the prism; and

a main reflector motor operable to move the main reflector.

6. The system of claim 1, wherein the one or more motors comprises:

a motor operating substantially at a periphery of the main reflector.

7. The system of claim 1, wherein the prism is operable to refract the signal in a refraction direction by:

refracting the signal a plurality of times.

8. The system of claim 1, further comprising the subreflector, the subreflector operable to:

receive the signal from an antenna feed; and

reflect the signal.

9. The system of claim 1, the main reflector further comprising a printed circuit board with a frequency selective surface (FSS) patterned in the asymmetrical pattern.

10. A method for steering a beam, comprising:

receiving at a main reflector a signal from a subreflector, the main reflector having an asymmetrical pattern;

reflecting the signal from the main reflector in a reflection direction, the asymmetrical pattern yielding the reflection direction different from a boresight axis;

refracting at a prism the signal in a refraction direction; and

adjusting by one or more motors a relative orientation between the main reflector and the prism to change a relative orientation between the reflection direction and the refraction direction to steer a beam resulting from the signal.

11. The method of claim 10, wherein:

at least one of the main reflector or the prism is operable to rotate substantially about a boresight axis; and

adjusting by the one or more motors the relative orientation between the main reflector and the prism further comprises;

rotating the at least one of the main reflector or the prism about the boresight axis.

12. The method of claim 10, wherein the main reflector has a pattern comprising:

a plurality of linear dipole elements; and

a plurality of crossed dipole elements.

13. The method of claim 10, wherein the prism comprises:

a plurality of zone steps; and

an anti-reflective layer operable to reduce reflection of the signal from the prism.

14. The method of claim 10, wherein adjusting by the one or more motors the relative orientation between the main reflector and the prism further comprises at least one of:

moving the prism using a prism motor; and

moving the main reflector using a main reflector motor.

15. The method of claim 10, wherein the one or more motors comprises:

a motor operating substantially at a periphery of the main reflector.

16. The method of claim 10, wherein refracting at a prism the signal in the refraction direction further comprises:

refracting the signal a plurality of times.

17. The method of claim 10, further comprising:

receiving at the subreflector the signal from an antenna feed; and

reflecting the signal from the subreflector.

18. The method of claim 10, the main reflector further comprising a printed circuit board with a frequency selective surface (FSS) patterned in the asymmetrical pattern.

19. A system for steering a beam, comprising:

means for receiving at a main reflector a signal from a subreflector, the main reflector having an asymmetrical pattern;

means for reflecting the signal from the main reflector in a reflection direction, the asymmetrical pattern yielding the reflection direction different from a boresight axis;

means for refracting at a prism the signal in a refraction direction; and

means for adjusting by one or more motors a relative orientation between the main reflector and the prism to change a relative orientation between the reflection direction and the refraction direction to steer a beam resulting from the signal.

20. A system for steering a beam, comprising:

a subreflector operable to;

receive a signal from an antenna feed; and

reflect the signal;

a main reflector operable to;

receive the signal from the subreflector; and

reflect the signal in a reflection direction, the main reflector having an asymmetrical pattern that yields the reflection direction different from a boresight axis, comprising;

a plurality of linear dipole elements; and

a plurality of crossed dipole elements;

a prism coupled to the main reflector and operable to;

refract the signal in a refraction direction by refracting the signal a plurality of times, at least one of the main reflector or the prism operable to rotate substantially about the boresight axis, the prism comprising;

a plurality of zone steps; and

an anti-reflective layer operable to reduce reflection of the signal from the prism; and

one or more motors coupled to at least one of the main reflector or the prism, and operable to;

adjust a relative orientation between the main reflector and the prism to change a relative orientation between the reflection direction and the refraction direction to steer a beam resulting from the signal; and

adjust the relative orientation between the main reflector and the prism by;

rotating the at least one of the main reflector or the prism about the boresight axis, the one or more motors comprising at least one of;

a prism motor operable to move the prism; and

a main reflector motor operable to move the main reflector, the one or more motors comprising;

a motor operating substantially at a periphery of the main reflector.