Transmission medium having multiple cores and methods for use therewith

• US 9,490,869 B1
• Filed: 07/16/2015
• Issued: 11/08/2016
• Est. Priority Date: 05/14/2015
• Status: Active Grant

• Current Assignee: AT&T Intellectual Property I LP (AT&T, Inc.)
• Original Assignee: AT&T Intellectual Property I LP (AT&T, Inc.)
• Inventors: Taylor, William Scott, Henry, Paul Shala, Bennett, Robert, Barzegar, Farhad, Gerszberg, Irwin, Barnickel, Donald J., Willis, Thomas M. III
• Primary Examiner(s): Tran, Khai
• Application Number:
  US14/800,745
• Publication Number:
  US 20160336997A1
• Time in Patent Office: 481 Days
• Field of Search: 375/256, 375/257, 356/301, 333/4, 333/5, 333/238
• US Class Current: 1/1
• CPC Class Codes: H01P 3/06 Coaxial lines
• CPC Class Codes: H01P 3/16 Dielectric waveguides, i.e. without a longitudinal conductor
• CPC Class Codes: H04B 2203/5425 improving S/N by matching impedance, noise reduction, gain control
• CPC Class Codes: H04B 2203/5487 cables
• CPC Class Codes: H04B 3/32 Reducing cross-talk, e.g. by compensating
• CPC Class Codes: H04B 3/54 Systems for transmission via power distribution lines
• CPC Class Codes: H04B 3/56 Circuits for coupling, blocking, or by-passing of signals

Abstract

Aspects of the subject disclosure may include, for example, a transmission medium for propagating electromagnetic waves. The transmission medium can include a plurality of cores for selectively guiding an electromagnetic wave of a plurality of electromagnetic waves longitudinally along each core, and a shell surrounding at least a portion of each core for reducing exposure of the electromagnetic wave of each core. Other embodiments are disclosed.

Claims

1. A transmission medium, comprising:

a plurality of cables, each cable comprising a core; and

a dielectric layer surrounding at least a portion of each core of the plurality of cables, wherein each core is configured to enable an electromagnetic wave having a non-optical frequency range to be bound to the core rather than the dielectric layer without an electrical return path and to have an electric field intensity profile that is substantially concentrated within the dielectric layer, and wherein the dielectric layer reduces exposure of the electromagnetic wave to an adverse environment.

2. The transmission medium of claim 1, wherein the core of each cable comprises a conductor having an insulation layer disposed between the conductor and the dielectric layer.

3. The transmission medium of claim 2, wherein the insulation layer has a first dielectric constant, wherein the dielectric layer has a second dielectric constant, and wherein the first dielectric constant exceeds the second dielectric constant.

4. The transmission medium of claim 2, wherein the insulation layer comprises a high density dielectric material, and wherein the dielectric layer comprises a dielectric foam.

5. The transmission medium of claim 2, wherein the electromagnetic waves are bound to the insulation layer.

6. The transmission medium of claim 1, wherein the core of each cable comprises an uninsulated conductor, wherein the dielectric layer is disposed on an outer surface of the uninsulated conductor, and wherein the electromagnetic waves have a fundamental guided wave mode bound to the uninsulated conductor.

7. The transmission medium of claim 1, wherein the core of each cable comprises a non-conducting core, wherein a first portion of fields emitted by the electromagnetic waves is confined to the non-conducting core, and wherein a second portion of the fields is confined to the dielectric layer.

8. The transmission medium of claim 7, wherein the non-conducting core comprises a dielectric core.

9. The transmission medium of claim 8, wherein the dielectric core has a first dielectric constant, wherein the dielectric layer has a second dielectric constant, and wherein the first dielectric constant exceeds the first dielectric constant.

10. The transmission medium of claim 1, further comprising a cover that surrounds an outer surface of the dielectric layer to prevent exposure of the electromagnetic wave, and wherein the cover comprises a dielectric material.

11. The transmission medium of claim 10, wherein the core of each cable is opaque, thereby restricting a propagation of light waves in each core.

12. The transmission medium of claim 1, wherein the dielectric layer comprises a dielectric foam.

13. The transmission medium of claim 1, further comprising an absorption material that absorbs a portion of the electromagnetic wave to prevent cross-talk between the plurality of cables.

14. The transmission medium of claim 13, wherein absorption material comprises a carbon material.

15. A method, comprising:

receiving, by a transmission medium, a plurality signals supplied by a plurality of launchers, wherein each signal of the plurality signals conveys different data, and wherein the transmission medium comprises a plurality of cores without an electrical return path, each core surrounded at least in part by a shell; and

selectively coupling, by the transmission medium, to each signal of the plurality signals to generate guided electromagnetic waves at each of the plurality of cores each having an electric field intensity profile that is substantially concentrated within the shell, wherein the shell of a core reduces exposure of the guided electromagnetic waves of the core, and wherein the guided electromagnetic waves have a non-optical frequency range.

16. The method of claim 15, wherein the shell of each core comprises a dielectric foam disposed on an outer surface of the core, and wherein each of the plurality of cores is opaque, thereby restricting a propagation of light waves in each core.

17. The method of claim 15, wherein each core comprises a conductor having an insulation layer, and wherein the guided electromagnetic wave coupled to each core is bound to the insulation layer of the core.

18. The method of claim 15, wherein each core comprises an uninsulated conductor having an insulation layer, and wherein the guided electromagnetic wave coupled to each core is bound to the uninsulated conductor.

19. The method of claim 15, wherein each core comprises an opaque non-conductive core, wherein a first portion of fields emitted by the guided electromagnetic wave coupled to each core is confined within the non-conductive core and a second portion of the fields is confined within the shell.

20. The method of claim 15, further comprising polarizing, by selective cores of the transmission medium, the guided electromagnetic waves to reduce cross-talk between the plurality of cores.

21. The method of claim 15, wherein the guided electromagnetic waves of at least one of the plurality of cores has a propagation wave mode that reduces cross-talk between the plurality of cores.

22. A multi-guide cable, comprising:

a plurality of cores, each core having no electrical return path; and

a shell surrounding at least a portion of each core, wherein each core is configured to enable one of a plurality of electromagnetic waves having a non-optical frequency range to be bound to the core rather than the shell and to have an electric field intensity profile that is substantially concentrated within the shell, wherein each core is configured to have a reduced propagation loss for electromagnetic waves having the non-optical frequency range, and wherein the shell reduces exposure of the electromagnetic wave of each core.

23. The cable of claim 22, wherein each core of the plurality of cores comprises an antenna for radiating a signal that couples to a transmission medium.

24. The cable of claim 23, wherein each antenna comprises an exposed core stripped of its shell, and wherein the exposed core includes a tapered end.

25. The cable of claim 22, wherein each of the plurality of cores is opaque resulting in an increased propagation loss for transmitting light waves in each core, and the reduced propagation loss for transmitting electromagnetic waves having the non-optical frequency range.