Earth-ionosphere waveguide power transfer

Patent metadata

Field	Value
Publication number	US-10852333-B2
Application number	US-201715837343-A
Country	US
Kind code	B2
Filing date	Dec 11, 2017
Priority date	Dec 11, 2017
Publication date	Dec 1, 2020
Grant date	Dec 1, 2020

Abstract

Systems and methods for detecting low-loss eigenmodes of a spherical waveguide bounded by the Earth's surface and its ionosphere are disclosed. One or more eigenmodes of the Earth-ionosphere waveguide may be computed based on a mathematical model incorporating electrical properties of the terrestrial surface and plasma physics of the ionospheric layer. A transmitter apparatus may be used transmit electrical power into the Earth-ionosphere waveguide in the form of an electromagnetic wave, which may, in turn, be detected by a receiver apparatus remote from the transmitter apparatus. A coupling strength between the transmitted electromagnetic wave and the one or more eigenmodes may be determined by measuring power received by the receiver apparatus in the detected electromagnetic wave. By iteratively adjusting parameters of the transmitter apparatus, determining the coupling strength, and refining a quantitative description of the eigenmodes, the eigenmodes may be harnessed for wireless power transmission throughout the Earth-ionosphere waveguide.

First claim

What is claimed:

1. A method comprising:
transmitting, by a transmitter apparatus, electrical power into a spherical waveguide bounded by a terrestrial surface and an ionospheric layer, wherein the electrical power is transmitted in an electromagnetic wave;
computing one or more eigenmodes of the spherical waveguide based on a mathematical model of the spherical waveguide that incorporates electrical properties of the terrestrial surface and plasma physics of the ionospheric layer;
detecting the transmitted electromagnetic wave by a receiver apparatus remote from the transmitter apparatus; and
determining a strength of coupling between the transmitted electromagnetic wave and the one or more eigenmodes by measuring an amount of power received by the receiver apparatus in the detected electromagnetic wave,
wherein determining the strength of coupling between the transmitted electromagnetic wave and the one or more eigenmodes by measuring the amount of power received by the receiver apparatus in the detected electromagnetic wave comprises:
measuring electric and magnetic field vectors of the detected electromagnetic wave; and
comparing the measured electric and magnetic field vectors with computed electric and magnetic field vectors of the one or more eigenmodes at a spatial location in the mathematical model of the spherical waveguide corresponding to that of the receiver apparatus.

2. The method of claim 1 , wherein the terrestrial surface is the surface of the Earth and the ionospheric layer is the ionospheric layer of the Earth.

3. The method of claim 1 , wherein computing the one or more eigenmodes of the spherical waveguide comprises:
numerically solving Maxwell's Equations applied to the mathematical model of the spherical waveguide;
determining the one or more eigenmodes from the numerical solution in the form of computed electric and magnetic field vectors at discrete spatial points of the mathematical model of the spherical waveguide; and
determining eigenfrequencies and propagation constants for the one or more eigenmodes from the numerical solution.

4. The method of claim 3 , wherein numerically solving Maxwell's Equations applied to the mathematical model of the spherical waveguide comprises computing a numerical simulation in at least one of: two spatial dimensions, or three spatial dimensions.

5. The method of claim 3 , wherein transmitting the electrical power into the spherical waveguide comprises transmitting the electrical power at one or more of the eigenfrequencies.

6. The method of claim 1 , wherein transmitting the electrical power into the spherical waveguide comprises encoding particular information into the transmitted electromagnetic wave, and where detecting the transmitted electromagnetic wave by the receiver apparatus comprises detecting the encoded particular information.

7. The method of claim 6 , wherein the particular information comprises a timing signature.

8. The method of claim 1 , further comprising:
based on the determined strength of coupling, determining a statistical confidence that the detected electromagnetic wave was coupled to the one or more eigenmodes during a time interval in which it was detected by the receiver apparatus.

9. The method of claim 1 , wherein the one or more eigenmodes form standing waves of an electric and magnetic vector field,
wherein the receiver apparatus comprises a plurality of receiver devices, each at a different remote location from the transmitter apparatus,
and wherein determining the strength of coupling between the transmitted electromagnetic wave and the one or more eigenmodes further comprises:
predicting relative strengths of coupling among the plurality of receiver devices at each of the different remote locations based on standing waves; and
comparing relative power measurements among the plurality of receiver devices with the predicted relative strengths of coupling.

10. The method of claim 9 , wherein predicting relative strengths of coupling among the plurality of receiver devices at each of the different remote locations based on standing waves comprises:
computing a numerical simulation of the transmitted electromagnetic wave based on a mathematical model of transmission properties of the transmitter apparatus;
computing a discretized overlap integral between the one or more eigenmodes and the simulated transmitted electromagnetic wave at simulated locations corresponding to the different remote locations of the plurality of receivers; and
comparing the discretized overlap integral with an empirical overlap integral derived from measurements of electric and magnetic field vectors at the plurality of receiver devices.

11. The method of claim 1 , wherein the transmitter apparatus comprises a plurality of electrically connected waveguide coupling elements,
wherein transmitting electrical power into the spherical waveguide by the transmitter apparatus comprises transmitting electrical power by two or more waveguide coupling elements of the plurality while maintaining relative phases between the two or more waveguide coupling elements.

12. The method of claim 11 , wherein the method further comprises:
predicting a relative change in the coupling strength between the transmitted electromagnetic wave and the one or more eigenmodes that would result from one or more given changes in the relative phases between the two or more waveguide coupling elements;
predicting a change in the amount of power received by the receiver apparatus in the detected electromagnetic wave based on the predicted relative change in coupling strength;
adjusting the relative phases between the two or more waveguide coupling elements by the one or more given changes in the relative phases during transmission; and
determining whether or not a measured change in power received at the receiver apparatus is within a threshold of the predicted change in received power.

13. A system comprising:
a transmitter apparatus;
a receiver apparatus remote from the transmitter apparatus; and
a computer apparatus having one or more processors and memory storing instructions that, when executed by the one or more processors, cause the system to carry out operations including:
causing the transmitter apparatus to transmit electrical power into a spherical waveguide bounded by the terrestrial surface of the Earth and the ionospheric layer of the Earth, wherein the electrical power is transmitted in an electromagnetic wave;
computing one or more eigenmodes of the spherical waveguide based on a mathematical model of the spherical waveguide that incorporates electrical properties of the terrestrial surface and plasma physics of the ionospheric layer;
causing the receiver apparatus to detect the transmitted electromagnetic wave; and
determining a strength of coupling between the transmitted electromagnetic wave and the one or more eigenmodes by measuring an amount of power received by the receiver apparatus in the detected electromagnetic wave,
wherein determining the strength of coupling between the transmitted electromagnetic wave and the one or more eigenmodes by measuring the amount of power received by the receiver apparatus in the detected electromagnetic wave comprises:
measuring electric and magnetic field vectors of the detected electromagnetic wave; and
comparing the measured electric and magnetic field vectors with computed electric and magnetic field vectors of the one or more eigenmodes at a spatial location in the mathematical model of the spherical waveguide corresponding to that of the receiver apparatus.

14. The system of claim 13 , wherein computi

Assignees

• X Dev Llc

Inventors

• Adolf Brian John

Classifications

• G01R27/04 Primary

  in circuits having distributed constants {, e.g. having very long conductors or involving high frequencies} · CPC title

• H02J50/402 Primary

  the two or more transmitting or the two or more receiving devices being integrated in the same unit, e.g. power mats with several coils or antennas with several sub-antennas · CPC title

• G01R21/133

  by using digital technique · CPC title

• H02J50/90

  involving detection or optimisation of position, e.g. alignment · CPC title

• H02J50/05

  using capacitive coupling · CPC title