Active Electronically Scanned Array Antenna for Hemispherical Scan Coverage

• US 20120133549A1
• Filed: 11/29/2010
• Published: 05/31/2012
• Est. Priority Date: 11/29/2010
• Status: Active Grant

• Current Assignee: SRC, Inc.
• Original Assignee: SRC, Inc.
• Inventors: Culkin, Daniel R., Graham, Timothy David
• Granted Patent: US 8,547,275 B2
• Time in Patent Office: Days
• US Class Current: 342/195
• CPC Class Codes: G01S 13/4463 using phased arrays
• CPC Class Codes: H01Q 21/20 the units being spaced along or adjacent to a curvilinear path slotted waveguide arrays H01Q21/005; circularly or helically slotted waveguides H01Q21/0062
• CPC Class Codes: H01Q 21/205 providing an omnidirectional coverage turnstile aerials H01Q21/26
• CPC Class Codes: H01Q 9/285 Planar dipole H01Q9/065 takes precedence; patch antenna H01Q9/0407

Abstract

An antenna architecture for hemispherically-scanning active electronically scanned arrays (AESA). The antenna architecture utilizes variable diameter disks of antenna elements configured in a conical implementation. The antenna elements are oriented such that the element boresight is normal to the surface of the conical structure. Beamforming takes place on each disk first, and them separately in combining the signals from each disk, thereby reducing complexity. The antenna optionally utilizes disks of antenna elements of the same diameter to form a cylindrical antenna, which when combined with a conical configuration create enhanced sectors while maintaining a hemispherical coverage capability. Further, use of two conical configurations can produce a fully spherical coverage capability.

Claims

1. An AESA antenna architecture comprising:

a first region comprising a first plurality of antenna elements arranged on the exterior circumference of a first plurality of platters, said platters forming a generally cylindrical array;

a second region comprising a second plurality of antenna elements arranged on the exterior circumference of a second plurality of platters, said platters forming a generally conical array; and

a plurality of amplitude/phase modules, wherein each of said plurality of amplitude/phase modules is coupled to at least two antenna elements.

2. The antenna architecture of claim 1, wherein each of said first and second plurality of platters is circular.

3. The antenna architecture of claim 2, wherein said first plurality of platters are stacked to form said generally cylindrical array.

4. The antenna architecture of claim 2, wherein said second plurality of platters are stacked to form said generally conical array.

5. The antenna architecture of claim 4, wherein the diameter of each of second plurality of platters gradually decreases from a platter having a maximum diameter at the base of said generally conical array to a platter having a minimum diameter at the top of said generally conical array.

6. The antenna architecture of claim 1, further comprising a beamforming network.

7. The antenna architecture of claim 1, wherein each amplitude/phase module comprises a sum (Σ

) azimuth beam path and a delta (Δ

) azimuth beam path.

8. The antenna architecture of claim 7, wherein the sum (Σ

) azimuth beam paths and the delta (Δ

) azimuth beam paths from each platter are combined.

10. The method according to claim 1, further comprising the step of converting each of said single sum (Σ

) azimuth beam and said single delta (Δ

) azimuth beam to a digital signal prior to forming said elevation beam.

11. The method according to claim 1, wherein a first subset of said plurality of platters are stacked to form a generally cylindrical region, and a second subset of said plurality of platters, the diameter of each platter in said second subset gradually decreasing from a platter having a maximum diameter at the base of a generally conical array to a platter having a minimum diameter at the top of a generally conical array.

12. The method according to claim 1, wherein said first subset is all of said plurality of antenna elements.

13. The method according to claim 1, further comprising the step of downconverting said calculated sum (Σ

) azimuth beam and said calculated delta (Δ

) azimuth beam.

14. The method according to claim 1, further comprising the step of demodulating said digital signal.

15. The method according to claim 1, further comprising the step of amplifying said received signal.

9. A method for radar target detection comprising the steps:

providing an antenna comprising a plurality of antenna elements arranged on the exterior circumference of a plurality of platters, and a plurality of amplitude/phase modules, wherein each of said plurality of amplitude/phase modules is coupled to at least two antenna elements;

selecting a first subset of said plurality of antenna elements;

receiving a signal at said antenna;

calculating a sum (Σ

) azimuth beam and a delta (Δ

) azimuth beam for each amplitude/phase module which is coupled to an antenna element in said selected first subset;

combining each sum (Σ

) azimuth beam and a delta (Δ

) azimuth beam from every amplitude/phase module on each platter into a single sum (Σ

) azimuth beam and a single delta (Δ

) azimuth beam for that platter; and

forming an elevation beam.

16. A radar system comprising:

an antenna comprising a plurality of antenna elements arranged on the exterior circumference of a plurality of platters, and a plurality of amplitude/phase modules, wherein each of said plurality of amplitude/phase modules is coupled to at least two antenna elements;

means for selecting a first subset of said plurality of antenna elements;

means for receiving a signal at said antenna;

means for calculating a sum (Σ

) azimuth beam and a delta (Δ

) azimuth beam for each amplitude/phase module which is coupled to an antenna element in said selected first subset;

means for combining each sum (Σ

) azimuth beam and a delta (Δ

) azimuth beam from every amplitude/phase module on each platter into a single sum (Σ

) azimuth beam and a single delta (Δ

) azimuth beam for that platter; and

means for forming an elevation beam.

17. The radar system of claim 16, further comprising means for converting each of said single sum (Σ

) azimuth beam and said single delta (Δ

) azimuth beam to a digital signal prior to forming said elevation beam.

18. The radar system of claim 16, further comprising means for downconverting said calculated sum (Σ

) azimuth beam and said calculated delta (Δ

) azimuth beam.

19. The radar system of claim 16, further comprising means for demodulating said digital signal.

20. The radar system of claim 16, further comprising means for amplifying said received signal.