MULTIPLE POLARIZATION LOOP ANTENNA AND ASSOCIATED METHODS

• US 20080136720A1
• Filed: 12/11/2006
• Published: 06/12/2008
• Est. Priority Date: 12/11/2006
• Status: Active Grant

• Current Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Original Assignee: Harris Corporation (L3Harris Technologies, Inc.)
• Inventors: Parsche, Francis Eugene, Tebbe, Dennis Lee
• Granted Patent: US 8,847,832 B2
• Time in Patent Office: Days
• US Class Current: 343/741
• CPC Class Codes: H01Q 21/24 Combinations of antenna units polarised in different directions for transmitting or receiving circularly and elliptically polarised waves or waves linearly polarised in any direction circularly polarised patch antennas H01Q9/0428; circularly polarised horns H01Q13/0241; cross-polarised horns H01Q13/0258; polarisation converters H01Q15/242; cross-polarised rear feeds H01Q19/136; crossed polarisation dual antenna H01Q25/001
• CPC Class Codes: H01Q 25/00 Antennas or antenna systems providing at least two radiating patterns arrangements for changing or varying the orientation or the shape of the directional pattern H01Q3/00
• CPC Class Codes: H01Q 7/00 Loop antennas with a substantially uniform current distribution around the loop and having a directional radiation pattern in a plane perpendicular to the plane of the loop
• CPC Class Codes: Y10T 29/49016 Antenna or wave energy "plumbing" making

Abstract

The multiple polarization loop antenna includes a circularly polarized loop antenna, which may utilize a loop electrical conductor and two signal feedpoints along the loop electrical conductor separated by one quarter of the length of the loop circumference for a signal feedpoint phase angle input difference of 90 degrees. Each of the signal feedpoints may include a loop discontinuity, so that at least one signal source coupled thereto provides circular polarization from the loop electrical conductor. The circularly polarized loop antenna provides an increase in gain and decrease in size relative to the dipole turnstile. It can provide two orthogonal polarizations from two isolated ports, and the polarizations may be dual linear or dual circular.

Claims

1. A circularly polarized loop antenna comprising:

a loop electrical conductor; and

two signal feedpoints along the loop electrical conductor and separated by one quarter of a length of the loop electrical conductor for a signal feedpoint phase angle input difference of 90 degrees;

each of said signal feedpoints comprising a series signal feedpoint so that at least one signal source coupled thereto provides circular polarization for said loop electrical conductor.

2. The circularly polarized loop antenna according to claim 1, wherein each of said series signal feedpoints defines a discontinuity in said loop electrical conductor.

3. The circularly polarized loop antenna according to claim 1, wherein said loop electrical conductor comprises a circular electrical conductor.

4. The circularly polarized loop antenna according to claim 1, wherein at least one of said signal feedpoints further comprises a two-wire transmission line connected in series at said respective series signal feedpoint.

5. The circularly polarized loop antenna according to claim 1, further comprising a feed structure including a direct leg and a phase inducing leg connected in parallel to corresponding ones of said series signal feedpoints.

6. The circularly polarized loop antenna according to claim 1, further comprising a quadrature hybrid feed structure, connected to said series signal feedpoints.

7. The circularly polarized loop antenna according to claim 1, wherein each of the signal feedpoints is a shunt connection across a continuous loop electrical conductor.

8. A circularly polarized loop antenna comprising:

a loop electrical conductor;

a plurality of signal feedpoints along the loop electrical conductor;

each of said signal feedpoints comprising a series signal feedpoint so that at least one signal source coupled thereto provides circular polarization for said loop electrical conductor.

9. The circularly polarized loop antenna according to claim 8, wherein each of said series signal feedpoints defines a discontinuity in said loop electrical conductor.

10. The circularly polarized loop antenna according to claim 8, wherein said loop electrical conductor comprises a circular electrical conductor.

11. The circularly polarized loop antenna according to claim 8, wherein each of said signal feedpoints further comprises a two-wire transmission line connected in series at said respective series signal feedpoint.

12. The circularly polarized loop antenna according to claim 8, further comprising a feed structure including a direct leg and a phase inducing leg connected in parallel to corresponding ones of said series signal feedpoints.

13. A method of making a circularly polarized loop antenna comprising:

forming an electrical conductor into a loop; and

forming a plurality of signal feedpoints along the loop electrical conductor, each of the signal feedpoints comprising a series signal feedpoint so that at least one signal source connected to the series feedpoints provides circular polarization for the loop electrical conductor.

15. The method according to claim 15, wherein forming the loop electrical conductor comprises forming a circular electrical conductor.

14. The method according to claim 15, wherein forming the plurality of signal feed points comprises forming discontinuities in the loop electrical conductor.

16. The method according to claim 15, wherein providing the plurality of signal feed points further comprises connecting a two-wire transmission line in series at the respective series signal feedpoint.

17. The method according to claim 15, further comprising connecting a feed structure including a direct leg and a phase inducing leg connected in parallel to corresponding ones of the series signal feedpoints.

18. A dual linearly polarized loop antenna comprising:

a loop electrical conductor; and

two signal feedpoints along the loop electrical conductor and separated by one quarter of a length of the loop electrical conductor and operated at a signal feedpoint phase angle input difference of 0 degrees;

each of said signal feedpoints comprising a series signal feedpoint so that at least one signal source coupled thereto provides dual linear polarization for said loop electrical conductor.

19. The dual linearly polarized loop antenna according to claim 18, wherein each of said series signal feedpoints defines a discontinuity in said loop electrical conductor.

20. The dual linearly polarized loop antenna according to claim 18, wherein said loop electrical conductor comprises a circular electrical conductor.