Enhanced guided surface waveguide probe

• US 9,893,403 B2
• Filed: 08/16/2016
• Issued: 02/13/2018
• Est. Priority Date: 09/11/2015
• Status: Active Grant

• Current Assignee: Quantum Wave LLC (Mad Energy)
• Original Assignee: Cpg Technologies, LLC
• Inventors: Corum, James F., Corum, Kenneth L.
• Primary Examiner(s): Takaoka, Dean
• Assistant Examiner(s): Wong, Alan
• Application Number:
  US15/238,041
• Publication Number:
  US 20170077893A1
• Time in Patent Office: 546 Days
• Field of Search: 333240, 333 24 R
• 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 comprising a upper terminal portion coupled to a lower terminal portion through a variable capacitance. In another example, a method includes positioning the charge terminal at a defined height over a lossy conducting medium; adjusting a phase delay (Φ) of a feed network connected to the charge a terminal to match a wave tilt angle (Ψ) corresponding to a complex Brewster angle of incidence (θ_i,B) associated with the lossy conducting medium; adjusting the variable capacitance based upon an image ground plane impedance (Z_in) associated with the lossy conducting medium; and exciting the charge terminal with an excitation voltage via the feed network. The excitation voltage can establish an electric field that couples into a guided surface waveguide mode along a surface of the lossy conducting medium.

Claims

1. A method, comprising:

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

adjusting a phase delay (Φ

) of a feed network connected to the charge terminal to match a wave tilt angle (Ψ

) corresponding to a complex Brewster angle of incidence (θ

_i,B) associated with the lossy conducting medium;

adjusting the variable capacitance of the charge terminal based upon an image ground plane impedance (Z_in) associated with the lossy conducting medium; and

exciting the charge terminal with an excitation voltage via the feed network, where the excitation voltage establishes an electric field that couples into a guided surface waveguide mode along a surface of the lossy conducting medium.

2. The method of claim 1, wherein the variable capacitance of the charge terminal is adjusted based upon a reactive component of the image ground plane impedance (Z_in).

3. The method of claim 2, 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.

4. The method of claim 1, wherein the phase delay (Φ

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

5. The method 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.

6. The method of claim 1, wherein the complex Brewster angle of incidence (θ

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

7. The method of claim 6, wherein the characteristics of the lossy conducting medium include conductivity and permittivity.

8. The method of claim 1, 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.

9. The method of claim 8, wherein the physical boundary of the lossy conducting medium and the conducting image ground plane are separated by a complex depth.

10. The method of claim 1, comprising:

sensing a change in a 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 change in the 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.

11. The method of claim 1, wherein the lossy conducting medium is a terrestrial medium.

12. 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 configured to couple an excitation source to the charge terminal, the feed network configured to provide a voltage to the charge terminal with a phase delay (Φ

) that matches a wave tilt angle (Ψ

) associated with a complex Brewster angle of incidence (θ

_i,B) associated with the lossy conducting medium, and the variable capacitance is determined based upon an image ground plane impedance (Z_in) associated with the lossy conducting medium.

13. The guided surface waveguide probe of claim 12, 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.

14. The guided surface waveguide probe of claim 13, wherein the coil is a helical coil.

15. The guided surface waveguide probe of claim 13, wherein the charge terminal is coupled to the coil via a tap connection.

16. The guided surface waveguide probe of claim 12, wherein the feed network is configured to vary the phase delay (Φ

) to match the wave tilt angle (Ψ

).

17. The guided surface waveguide probe of claim 12, comprising a probe control system configured to adjust the feed network based at least in part upon characteristics of the lossy conducting medium.

18. The guided surface waveguide probe of claim 17, wherein the probe control system adjusts the variable capacitance in response to a change in the characteristics of the lossy conducting medium.

19. The guided surface waveguide probe of claim 18, wherein the probe control system adjusts the phase delay (Φ

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

20. The guided surface waveguide probe of claim 18, wherein the variable capacitance of the charge terminal is adjusted to match a 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.