Dual polarized multifilar antenna

• US 7,817,101 B2
• Filed: 10/19/2007
• Issued: 10/19/2010
• Est. Priority Date: 10/24/2006
• Status: Expired due to Fees

• Current Assignee: Com Dev Limited (Honeywell International Inc.)
• Original Assignee: Com DEV International Limited (Honeywell International Inc.)
• Inventors: Cowles, Philip R.
• Primary Examiner(s): Le; HoangAnh T
• Application Number:
  US11/875,547
• Publication Number:
  US 20080094308A1
• Time in Patent Office: 1,096 Days
• Field of Search: 343/895
• US Class Current: 343/895
• CPC Class Codes: H01Q 1/08 Means for collapsing antennas or parts thereof collapsible loop antennas H01Q7/02; means for collapsing H-antennas or Yagi antennas H01Q19/04
• CPC Class Codes: H01Q 11/08 Helical antennas
• 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 21/26 Turnstile or like antennas comprising arrangements of three or more elongated elements disposed radially and symmetrically in a horizontal plane about a common centre
• CPC Class Codes: H01Q 9/27 Spiral antennas

Abstract

Various embodiments are described of an antenna including a common ground plane, a first set of N approximately resonant elements with a length I2 and a second set of M approximately resonant elements with a length I1. The first set of N approximately resonant elements are wound to form a first helix with an initial diameter d2 and a height h2. The second set of M approximately resonant elements are wound in the opposite direction to the first set of N approximately resonant elements to form a second helix. The second helix is centrally disposed within the first helix, and d1 is less than d2 and h1 is greater than h2.

Claims

1. An antenna comprising:

a common ground plane;

a first set of N approximately resonant elements associated with the common ground plane, each of said first set of approximately resonant elements having a length I2 and wound to form a first helix with an initial diameter d2 and a height h2; and

a second set of N approximately resonant elements associated with the common ground plane, each of said second set of approximately resonant elements having a length I1 and wound in the opposite direction to the first set of approximately resonant elements to form a second helix that is centrally disposed within the first helix, and has an initial diameter dl and a height h1 where d1 is less than d2 and h1 is greater than h2,

wherein the length I2 of the first set of approximately resonant elements is about equal to the length I1 of the second set of approximately resonant elements, and wherein the first and second helices are simultaneously operable at the same frequency (f).

2. The antenna of claim 1, wherein N is greater than or equal to three.

3. The antenna of claim 1, wherein N is equal to three and the first and second helices are trifilar helices.

4. The antenna of claim 1, wherein N is equal to four and the first and second helices are quadrifilar helices.

5. The antenna of claim 1, wherein the approximately resonant elements each have a first end and a second end and the second ends are open-circuited.

6. The antenna of claim 1, wherein the approximately resonant elements each have a first end and a second end and the second ends are short-circuited to one another by conductors.

7. The antenna of claim 1, wherein the length of all approximately resonant elements is about a half-wavelength (λ

/2).

8. The antenna of claim 1, wherein the length of all approximately resonant elements is about a quarter-wavelength (λ

/4).

9. The antenna of claim 1, wherein the length I2 of the first approximately resonant elements is greater than the length I1 of the second approximately resonant elements.

10. The antenna of claim 1, wherein the first and second set of approximately resonant elements are cylindrically wound to form cylinders with a constant diameters.

11. The antenna of claim 1, wherein the first set of approximately resonant element are cylindrically wound to form a cylinder with a constant diameter and the second set of approximately resonant elements are wound to form a structure with a variable diameter.

12. The antenna of claim 1, wherein the first set of approximately resonant elements are wound to form a first structure with a variable diameter and the second set of approximately resonant elements are wound to form a second structure with a variable diameter.

13. The antenna of claim 1, wherein the first and second helices function as independently circularly polarized antennas.

14. The antenna of claim 1, wherein the first and second helices function as a single adaptive antenna.

15. The antenna of claim 1, wherein the first and second helices are compressible into a small volume.

16. The antenna of claim 1, wherein the common ground plane comprises at least one balanced feed network having a set of N feed elements.

17. The antenna of claim 1, wherein the common ground plane is a shared reflector.

18. The antenna of claim 1, wherein the second set of approximately resonant element are cylindrically wound to form a cylinder with a constant diameter and the first set of approximately resonant elements are wound to form a structure with a variable diameter.

19. A dual polarized multifilar antenna comprising:

a ground plane;

a first set of N resonant elements coupled to the ground plane and wound to form a first helical antenna; and

a second set of M resonant elements coupled to the ground plane and wound in an opposite direction to the first set of resonant elements to form a second helical antenna,

wherein, the first and second helical antennas are concentric, have different heights and diameters, the resonant elements of both helical elements have similar lengths, and the helical antennas are operable at substantially similar frequencies simultaneously.

20. The antenna of claim 19, wherein N and M are integers with values greater than or equal to three.