Coaxial cable and method of making same

• US 6,800,809 B2
• Filed: 02/14/2000
• Issued: 10/05/2004
• Est. Priority Date: 08/14/1997
• Status: Expired due to Term

• Current Assignee: CommScope Inc. (CommScope Holding Company, Inc.)
• Original Assignee: Commscope Solutions Properties LLC (CommScope Holding Company, Inc.)
• Inventors: Moe, Alan N., Adams, Scott M., Vacarro, Ronald, Carlson, Bruce J.
• Primary Examiner(s): Nguyen, Chau N.
• Application Number:
  US09/485,656
• Publication Number:
  US 20020053446A1
• Time in Patent Office: 1,695 Days
• Field of Search: 174/106.R, 174/107, 174/36, 174/102.R, 174/110.F, 174/120.R, 174/126.4, 333/243, 333/12
• US Class Current: 174/102.00R
• CPC Class Codes: H01B 11/1804 Construction of the space inside the hollow inner conductor
• CPC Class Codes: H01B 11/1826 Co-axial cables with at least one longitudinal lapped tape-conductor
• CPC Class Codes: H01B 11/1839 of cellular structure
• CPC Class Codes: H01B 13/016 for manufacturing co-axial cables applying discontinuous insulation H01B13/20

Abstract

The present invention is a flexible low loss coaxial cable comprising a cylindrical plastic rod, an inner conductor surrounding the plastic rod, a dielectric layer surrounding the inner conductor, and a tubular metallic sheath closely surrounding the dielectric layer. The coaxial cable can further include a protective polymer jacket surrounding the sheath. The cylindrical plastic rod supports the inner conductor in bending and can be formed around a central structural member. The present invention also includes a method of making flexible coaxial cable.

Claims

1. A coaxial cable comprising:

a cylindrical plastic rod;

an electrically conductive tubular inner conductor surrounding said plastic rod, provided by forming a metal strip into a tubular configuration with the longitudinal side edges of the strip butted together and joined by a continuous longitudinal weld, and adhesively bonded to the plastic rod;

a continuous foam polymer dielectric layer closely surrounding the inner conductor; and

a tubular metallic outer sheath closely surrounding the foam polymer dielectric layer.

2. The coaxial cable of claim 1 wherein said metallic sheath has a diameter of more than 1.0 inches (2.5 cm).

3. The coaxial cable of claim 1 wherein the ratio of the thickness of the metallic sheath to the outer diameter of the metallic sheath is no greater than 1.0 percent.

4. The coaxial cable of claim 1 further comprising a central structural member within said cylindrical plastic rod such that said central structural member supports said rod.

5. The coaxial cable of claim 4 wherein said central structural member comprises a reinforced plastic material or a metallic material.

6. The coaxial cable of claim 1 wherein said plastic rod is a closed cell foam plastic rod.

7. The coaxial cable of claim 1 further comprising a solid dielectric between said foam polymer dielectric layer and said sheath.

8. The coaxial cable of claim 1 wherein the density of said foam polymer dielectric layer increases radially from said inner conductor to said sheath.

9. The coaxial cable according to claim 1 wherein said inner conductor is copper, said foam polymer layer is adhesively bonded to said inner conductor, and said tubular metallic outer sheath is copper, said coaxial cable further comprising a protective polymer jacket surrounding said outer sheath and adhesively bonded thereto.

10. The coaxial cable according to claim 1 wherein said foam polymer dielectric layer is continuous from the inner conductor to the tubular metallic outer sheath.

11. The coaxial cable of claim 1 wherein said plastic rod is a hollow plastic rod.

12. The coaxial cable of claim 1 wherein said plastic rod is a continuous plastic rod.

13. The coaxial cable of claim 1 further comprising an adhesive layer between said inner conductor and said foam polymer dielectric layer.

14. The coaxial cable of claim 13, further comprising a solid polymer layer between said adhesive layer surrounding said inner conductor and said foam polymer dielectric layer.

15. The coaxial cable of claim 1 wherein said inner conductor is copper.

16. The coaxial cable of claim 1 wherein said foam polymer dielectric layer is adhesively bonded to said inner conductor.

17. The coaxial cable of claim 1 wherein said tubular metallic sheath is adhesively bonded to said foam polymer dielectric layer.

18. The coaxial cable of claim 1 further comprising a protective polymer jacket surrounding said outer sheath.