Enhanced guided surface waveguide probe

• US 10,326,190 B2
• Filed: 01/24/2018
• Issued: 06/18/2019
• Est. Priority Date: 09/11/2015
• Status: Active Grant

• Current Assignee: Quantum Wave LLC
• Original Assignee: Cpg Technologies, LLC
• Inventors: Corum, James F., Corum, Kenneth L.
• Primary Examiner(s): Takaoka, Dean O
• Assistant Examiner(s): Wong, Alan
• Application Number:
  US15/878,607
• Publication Number:
  US 20180151934A1
• Time in Patent Office: 510 Days
• CPC Class Codes: H01P 3/00 Waveguides; Transmission lines of the waveguide type
• CPC Class Codes: H01P 5/04 with variable factor of coupling
• CPC Class Codes: H01Q 1/04 Adaptation for subterranean or subaqueous use
• CPC Class Codes: H01Q 9/04 Resonant antennas
• CPC Class Codes: H01Q 9/32 Vertical arrangement of element H01Q9/40 takes precedence
• CPC Class Codes: H02J 50/20 using microwaves or radio frequency waves
• CPC Class Codes: H03H 7/004 Capacitive coupling circuits not otherwise provided for
• CPC Class Codes: H03H 7/20 Two-port phase shifters providing an adjustable phase shift
• CPC Class Codes: H03H 7/38 Impedance-matching networks
• CPC Class Codes: H04B 3/52 Systems for transmission between fixed stations via waveguides

Abstract

Various examples are provided for enhanced guided surface waveguide probes, systems and methods. In one example, a guided surface waveguide probe includes a charge terminal elevated over a lossy conducting medium, the charge terminal includes a upper terminal portion coupled to a lower terminal portion through a variable capacitance. A feed network is configured to couple an excitation source to the charge terminal and provide a voltage to the charge terminal with a phase delay that matches a wave tilt angle associated with a complex Brewster angle of incidence associated with the lossy conducting medium. In another example a method includes positioning a charge terminal over a lossy conducting medium, where the charge terminal includes an upper terminal portion coupled to a lower terminal portion through a variable capacitance. The method also includes adjusting a phase delay of a feed network to match a wave tilt angle associated with a complex Brewster angle of incidence associated with the lossy conducting medium, where the feed network is configured to couple an excitation source to the charge terminal and provide a voltage to the charge terminal with the phase delay.

Claims

1. A guided surface waveguide probe, comprising:

a charge terminal elevated over a lossy conducting medium, the charge terminal comprising a upper terminal portion coupled to a lower terminal portion through a variable capacitance; and

a feed network that couples an excitation source to the charge terminal and provides a voltage to the charge terminal with a phase delay (Φ

) that matches a wave tilt angle (Ψ

) of a Zenneck surface wave generated by the guided surface wave probe, the wave tilt angle (Ψ

) being associated with a complex Brewster angle of incidence (θ

_i,B) associated with the lossy conducting medium.

2. The guided surface waveguide probe of claim 1, wherein the feed network comprises a feed line conductor coupled to the charge terminal and a coil coupled between the lossy conducting medium and the feed line conductor, where the phase delay (Φ

) of the feed network includes a phase delay (θ

_y) associated with the feed line conductor and a phase delay (θ

_c) associated with the coil.

3. The guided surface waveguide probe of claim 2, wherein the coil is a helical coil.

4. The guided surface waveguide probe of claim 2, wherein the charge terminal is coupled to the coil via a tap connection.

5. The guided surface waveguide probe of claim 1, wherein the feed network is configured to vary the phase delay (Φ

) to match the wave tilt angle (Ψ

).

6. The guided surface waveguide probe of claim 1, comprising a probe control system configured to adjust the feed network based at least in part upon characteristics of the lossy conducting medium.

7. The guided surface waveguide probe of claim 6, wherein the probe control system adjusts the phase delay (Φ

) of the feed network to match a modified wave tilt angle in response to changed characteristics of the lossy conducting medium, the modified wave tilt angle corresponding to a complex Brewster angle of incidence associated with the lossy conducting medium having the changed characteristics.

8. The guided surface waveguide probe of claim 1, wherein the variable capacitance of the charge terminal is adjusted based upon an image ground plane impedance (Z_in) associated with the lossy conducting medium.

9. A method, comprising:

positioning a charge terminal at a defined height over a lossy conducting medium, where the charge terminal comprises a upper terminal portion coupled to a lower terminal portion through a variable capacitance; and

adjusting a phase delay (Φ

) of a feed network to match a wave tilt angle (Ψ

) of a Zenneck surface wave generated by the charge terminal, the wave tilt angle (Ψ

) being associated with a complex Brewster angle of incidence (θ

_i,B) associated with the lossy conducting medium, where the feed network is configured to couple an excitation source to the charge terminal and provide a voltage to the charge terminal with the phase delay (Φ

).

10. The method of claim 9, wherein the lossy conducting medium is a terrestrial medium.

11. The method of claim 9, wherein the feed network comprises a feed line conductor coupled to the charge terminal and a coil coupled between the lossy conducting medium and the feed line conductor, where the phase delay (Φ

) of the feed network includes a phase delay (θ

_y) associated with the feed line conductor and a phase delay (θ

_c) associated with the coil.

12. The method of claim 9, wherein the complex Brewster angle of incidence (θ

_i,B) associated with the lossy conducting medium is based upon an operational frequency of the voltage and characteristics of the lossy conducting medium.

13. The method of claim 12, wherein the characteristics of the lossy conducting medium include conductivity and permittivity.

14. The method of claim 9, further comprising adjusting the variable capacitance of the charge terminal based upon an image ground plane impedance (Z_in) associated with the lossy conducting medium.

15. The method of claim 14, wherein the variable capacitance of the charge terminal is adjusted based upon a reactive component of the image ground plane impedance (Z_in).

16. The method of claim 15, wherein the variable capacitance of the charge terminal is adjusted to match the reactive component of the image ground plane impedance (Z_in) with a structure impedance (Z_base) associated with the feed network and the charge terminal.

17. The method of claim 14, wherein the image ground plane impedance (Z_in) is based at least in part upon a phase shift (θ

_d) between a physical boundary of the lossy conducting medium and a conducting image ground plane.

18. The method of claim 17, wherein the physical boundary of the lossy conducting medium and the conducting image ground plane are separated by a complex depth.

19. The method of claim 14, further comprising:

sensing a changed characteristic of the lossy conducting medium;

adjusting the phase delay (Φ

) of the feed network connected to the charge terminal to match a modified wave tilt angle in response to the changed characteristic of the lossy conducting medium, the modified wave tilt angle corresponding to a complex Brewster angle of incidence associated with the lossy conducting medium having the changed characteristic; and

adjusting the variable capacitance of the charge terminal based upon a new image ground plane impedance that is based upon the lossy conducting medium having the changed characteristic.

20. The method of claim 14, wherein the phase delay (Φ

) of the feed network is fixed while the variable capacitance of the charge terminal is adjusted.