Coaxial dielectric rod antenna with multi-frequency collinear apertures

• US 6,266,025 B1
• Filed: 01/12/2000
• Issued: 07/24/2001
• Est. Priority Date: 01/12/2000
• Status: Expired due to Fees

• Current Assignee: HRL Laboratories LLC (The Boeing Co.)
• Original Assignee: HRL Laboratories LLC (The Boeing Co.)
• Inventors: Bridges, William B., Popa, Adrian E.
• Primary Examiner(s): Wong, Don
• Assistant Examiner(s): TRAN, CHUC
• Application Number:
  US09/482,166
• Time in Patent Office: 559 Days
• Field of Search: 343/785, 343/786, 343/719, 343/854, 343/872, 343/873, 333/21.R, 333/248, 333/251, 333/239, 333/240, 333/284
• US Class Current: 343/785
• CPC Class Codes: H01Q 1/40 Radiating elements coated with or embedded in protective material
• CPC Class Codes: H01Q 13/24 constituted by a dielectric or ferromagnetic rod or pipe H01Q13/28 takes precedence
• 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 21/30 Combinations of separate antenna units operating in different wavebands and connected to a common feeder system
• CPC Class Codes: H01Q 5/47 with a coaxial arrangement of the feeds

Abstract

An antenna. The antenna includes a first dielectric antenna rod having a first dielectric constant. The first dielectric antenna rod is coupled to a first frequency transmission source for propagating first frequency band radiation from the first dielectric antenna rod into a medium having a medium dielectric constant. A second dielectric antenna rod is provided having a second dielectric constant. The second dielectric antenna rod is coupled to a second frequency transmission source for propagating second frequency band radiation from the second dielectric antenna rod into the medium. The first dielectric antenna rod is coaxially mounted within the second dielectric antenna rod. The first dielectric constant is greater than the second dielectric constant. The second dielectric constant is greater than the medium dielectric constant.

Claims

1. A method of structuring an antenna, comprising the steps of:

providing a first dielectric antenna rod having a first dielectric constant, the first dielectric antenna rod being coupled to a first frequency transmission source for propagating first frequency band radiation from the first dielectric antenna rod into a medium having a medium dielectric constant; and

coaxially mounting the first dielectric antenna rod within a second dielectric antenna rod having a second dielectric constant, the second dielectric antenna rod being coupled to a second frequency transmission source for propagating second frequency band radiation from the second dielectric antenna rod into the medium;

wherein the first dielectric constant is greater than the second dielectric constant and the second dielectric constant is greater than the medium dielectric constant.

2. The method of structuring an antenna of claim 1, wherein the first dielectric antenna rod is formed by:

forming an axial cylindrical cavity along the length of the second dielectric antenna rod;

filling the axial cylindrical cavity with a dielectric powder having the first dielectric constant; and

securing the dielectric powder within the axial cylindrical cavity with end plugs having the first dielectric constant located at respective proximal and distal ends of the second dielectric antenna rod.

3. The method of structuring an antenna of claim 2, wherein the second dielectric antenna rod is made of a thermoplastic resin and the dielectric powder is barium tetra-titanate or nickel-aluminum titanate.

4. The method of structuring an antenna of claim 1, wherein:

the first frequency transmission source is axially coupled to the first dielectric antenna rod; and

the second frequency transmission source is coupled to the second dielectric antenna by a transmission line axially offset from the second dielectric antenna rod.

5. The method of structuring an antenna of claim 1, wherein each of the first dielectric antenna rod and the second dielectric antenna rod has an operating beamwidth ratio of at least 2:

1, and thus the antenna has an operating beamwidth ratio of at least 4;

1.

6. The method of structuring an antenna of claim 1, wherein each of the first dielectric antenna rod and the second dielectric antenna rod may operate in widely separated frequency bands such as X-Band and W-Band.

7. The method of structuring an antenna of claim 1, wherein the first dielectric antenna rod is formed by:

forming an axial cylindrical cavity along the length of the second dielectric antenna rod;

filling the axial cylindrical cavity with a dielectric rod having the first dielectric constant; and

securing the dielectric rod within the axial cylindrical cavity with end plugs having the first dielectric constant located at respective proximal and distal ends of the second dielectric antenna rod.

8. The method of structuring an antenna of claim 1, wherein the difference between the first dielectric constant and the second dielectric constant is greater than about 3.

14. The antenna of claim 1, wherein:

the first frequency transmission source is axially coupled to the first dielectric antenna rod; and

the second frequency transmission source is coupled to the second dielectric antenna by a transmission line axially offset from the second dielectric antenna rod.

9. A method of structuring an antenna, comprising the steps of:

providing a first dielectric antenna rod having a first dielectric constant, the first dielectric antenna rod being coupled to a first frequency transmission source for propagating first frequency band radiation from the first dielectric antenna rod into a medium having a medium dielectric constant; and

coaxially mounting the first dielectric antenna rod within a second dielectric antenna rod having a second dielectric constant, the second dielectric antenna rod being coupled to a second frequency transmission source for propagating second frequency band radiation from the second dielectric antenna rod into the medium;

coaxially mounting the second dielectric antenna rod within a third dielectric antenna rod having a third dielectric constant, the third dielectric antenna rod being coupled to a third frequency transmission source for propagating third frequency band radiation from the third dielectric antenna rod into the medium;

wherein the first dielectric constant is greater than the second dielectric constant, the second dielectric constant is greater than the third dielectric constant, and the third dielectric constant is greater than the medium dielectric constant.

10. The method of structuring an antenna of claim 9, wherein each of the first dielectric antenna rod, the second dielectric antenna rod and the third dielectric antenna rod has an operating beamwidth ratio of at least 2:

1, and thus the antenna has an operating beamwidth ratio of at least 8;

1.

11. An antenna comprising:

a first dielectric antenna rod having a first dielectric constant, the first dielectric antenna rod being coupled to a first frequency transmission source for propagating first frequency band radiation from the first dielectric antenna rod into a medium having a medium dielectric constant; and

a second dielectric antenna rod having a second dielectric constant, the second dielectric antenna rod being coupled to a second frequency transmission source for propagating second frequency band radiation from the second dielectric antenna rod into the medium, the first dielectric antenna rod being coaxially mounted within the second dielectric antenna rod;

wherein the first dielectric constant is greater than the second dielectric constant and the second dielectric constant is greater than the medium dielectric constant.

12. The antenna of claim 11, wherein the second dielectric antenna rod includes an axial cylindrical cavity along the length of the second dielectric antenna rod, the axial cylindrical cavity being filled with a dielectric powder having the first dielectric constant, and the dielectric powder being secured within the axial cylindrical cavity by end plugs having the first dielectric constant and being located at respective proximal and distal ends of the second dielectric antenna rod.

13. The antenna of claim 12, wherein the second dielectric antenna rod is made of a thermoplastic resin and the dielectric powder is barium tetra-titanate or nickel-aluminum titanate.

15. The antenna of claim 11, wherein each of the first dielectric antenna rod and the second dielectric antenna rod has an operating beamwidth ratio of at least 2:

1, and thus the antenna has an operating beamwidth ratio of at least 4;

1.

16. The antenna of claim 11, wherein each of the first dielectric antenna rod and the second dielectric antenna rod may operate in widely separated frequency bands such as X-Band and W-Band.

17. The antenna of claim 11, wherein the difference between the first dielectric constant and the second dielectric constant is greater than about 3.

18. An antenna comprising:

a first dielectric antenna rod having a first dielectric constant, the first dielectric antenna rod being coupled to a first frequency transmission source for propagating first frequency band radiation from the first dielectric antenna rod into a medium having a medium dielectric constant; and

a second dielectric antenna rod having a second dielectric constant, the second dielectric antenna rod being coupled to a second frequency transmission source for propagating second frequency band radiation from the second dielectric antenna rod into the medium, the first dielectric antenna rod being coaxially mounted within the second dielectric antenna rod;

a third dielectric antenna rod having a third dielectric constant, the third dielectric antenna rod being coupled to a third frequency transmission source for propagating third frequency band radiation from the third dielectric antenna rod into the medium, the second dielectric antenna rod being coaxially mounted within the third dielectric antenna rod;

wherein the first dielectric constant is greater than the second dielectric constant, the second dielectric constant is greater than the third dielectric constant, and the third dielectric constant is greater than the medium dielectric constant.

19. The antenna of claim 18, wherein each of the first dielectric antenna rod, the second dielectric antenna rod and the third dielectric antenna rod has an operating beamwidth ratio of at least 2:

1, and thus the antenna has an operating beamwidth ratio of at least 8;

1.