Ferrite-enhanced metamaterials

Patent metadata

Field	Value
Publication number	US-10312597-B2
Application number	US-201514865600-A
Country	US
Kind code	B2
Filing date	Sep 25, 2015
Priority date	Sep 25, 2015
Publication date	Jun 4, 2019
Grant date	Jun 4, 2019

Abstract

A method and apparatus for tuning a metamaterial cell. A set of electromagnetic properties of a tunable element associated with the metamaterial cell may be tuned. A resonance of the metamaterial cell may be adjusted in response to the set of electromagnetic properties being tuned. A range of frequencies over which the metamaterial cell provides a negative index of refraction may be changed in response to the resonance of the metamaterial cell changing.

First claim

What is claimed is:

1. An apparatus comprising:
a metamaterial cell that has a negative index of refraction; and
a tunable element disposed on one side of the metamaterial cell, wherein tuning a set of electromagnetic properties of the tunable element adjusts a resonance of the metamaterial cell,
wherein the metamaterial cell comprises: a magnetic resonator and a conductive structure positioned relative to the magnetic resonator; and
wherein the magnetic resonator is a dual split ring resonator;
wherein the tunable element comprises a ferromagnetic material.

2. The apparatus of claim 1 , wherein the metamaterial cell further comprises:
a base that is transparent to an electromagnetic field having a natural frequency of the metamaterial cell, wherein the magnetic resonator is disposed on the base.

3. The apparatus of claim 1 further comprising:
a tuning device that tunes the set of electromagnetic properties of the tunable element to adjust the resonance of the metamaterial cell.

4. The apparatus of claim 3 , wherein the tuning device comprises:
a controllable voltage source that applies an electric field to the tunable element to tune an electric permittivity of the tunable element, thereby adjusting the resonance of the metamaterial cell.

5. The apparatus of claim 1 , wherein the set of electromagnetic properties includes at least one of an electric permittivity or a magnetic permeability.

6. The apparatus of claim 1 , wherein changing the set of electromagnetic properties of the tunable element adjusts the resonance of the metamaterial cell, to thereby adjust a frequency range over which the metamaterial cell yields the negative index of refraction.

7. The apparatus of claim 1 , wherein the metamaterial cell and the tunable element form a meta-unit that is one of a plurality of meta-units that together form a metamaterial structure.

8. An apparatus comprising:
a metamaterial cell that has a negative index of refraction; and
a tunable element disposed on one side of the metamaterial cell, wherein tuning a set of electromagnetic properties of the tunable element adjusts a resonance of the metamaterial cell;
wherein the metamaterial cell comprises: a magnetic resonator and a conductive structure positioned relative to the magnetic resonator;
wherein the conductive structure comprises: a first conductor and a second conductor;
wherein the tunable element comprises: a plurality of liquid crystals located within a reservoir between the first conductor and the second conductor.

9. The apparatus of claim 8 further comprising:
a tuning device that tunes the set of electromagnetic properties of the tunable element to adjust the resonance of the metamaterial cell.

10. The apparatus of claim 9 , wherein the tuning device comprises:
a controllable voltage source that applies an electric field to the tunable element to tune an electric permittivity of the tunable element, thereby adjusting the resonance of the metamaterial cell.

11. The apparatus of claim 8 , wherein the set of electromagnetic properties includes at least one of an electric permittivity or a magnetic permeability.

12. The apparatus of claim 8 , wherein changing the set of electromagnetic properties of the tunable element adjusts the resonance of the metamaterial cell, to thereby adjust a frequency range over which the metamaterial cell yields the negative index of refraction.

13. The apparatus of claim 8 , wherein the metamaterial cell and the tunable element form a meta-unit that is one of a plurality of meta-units that together form a metamaterial structure.

14. An apparatus comprising:
a metamaterial cell that has a negative index of refraction;
a tunable element disposed on one side of the metamaterial cell, wherein tuning a set of electromagnetic properties of the tunable element adjusts a resonance of the metamaterial cell; and
a tuning device that tunes the set of electromagnetic properties of the tunable element to adjust the resonance of the metamaterial cell;
wherein the tuning device comprises: a magnetic device that externally applies a magnetic field to the metamaterial cell to tune a magnetic permeability of the tunable element, thereby adjusting the resonance of the metamaterial cell.

15. The apparatus of claim 14 , wherein the set of electromagnetic properties includes at least one of an electric permittivity or a magnetic permeability.

16. The apparatus of claim 14 , wherein changing the set of electromagnetic properties of the tunable element adjusts the resonance of the metamaterial cell, to thereby adjust a frequency range over which the metamaterial cell yields the negative index of refraction.

17. The apparatus of claim 14 , wherein the metamaterial cell and the tunable element form a meta-unit that is one of a plurality of meta-units that together form a metamaterial structure.

18. An apparatus comprising:
a metamaterial cell that has a negative index of refraction; and
a tunable element disposed on one side of the metamaterial cell, wherein tuning a set of electromagnetic properties of the tunable element adjusts a resonance of the metamaterial cell;
wherein the tunable element comprises: a fluid mixture comprising a plurality of liquid crystals and a plurality of magnetic nanoparticles, wherein tuning at least one of an electric permittivity of the plurality of liquid crystals or a magnetic permeability of the plurality of magnetic nanoparticles adjusts the resonance of the metamaterial cell.

19. A metamaterial structure comprising:
a plurality of meta-units, wherein a meta-unit in the plurality of meta-units comprises:
a metamaterial cell; and
a tunable element disposed on one side of the metamaterial cell;
wherein tuning at least one of an electric permittivity or a magnetic permeability of the tunable element adjusts a resonance of the metamaterial cell; and
wherein adjusting the resonance for at least a portion of the plurality of meta-units adjusts a frequency range over which the metamaterial structure provides a negative index of refraction for focusing electromagnetic energy;
wherein the metamaterial cell comprises: a magnetic resonator and a conductive structure positioned relative to the magnetic resonator;
wherein the magnetic resonator is a dual split ring resonator; and
wherein the tunable element comprises a ferromagnetic material.

20. A method for tuning a metamaterial cell, the method comprising:
tuning a set of electromagnetic properties of a tunable element disposed on one side of the metamaterial cell;
adjusting a resonance of the metamaterial cell in response to the set of electromagnetic properties being tuned; and
changing a range of frequencies over which the metamaterial cell provides a negative index of refraction in response to the resonance of the metamaterial cell changing;
wherein tuning the set of electromagnetic properties comprises: tuning an electric permittivity of a plurality of liquid crystals located within a reservoir disposed on the one side of the metamaterial cell to adjust the resonance of the metamaterial cell.

21. The method of claim 20 further comprising:
applying, externally, a magnetic field to the metamaterial cell to adjust the resonance of the metamaterial cell.

22. A method for tuning a metamaterial cell, the method comprising:
tuning a set of electromagnetic properties of a tunable element disposed on one side of the metamaterial cell;
adjusting a resonance of the metamaterial cell in respon

Assignees

• Boeing Co

Inventors

• Savage Larry Leon
• Williams John Dalton
• Thacker Corey Mckinney
• Fortinberry Jarrod Douglas
• Bushey Preston Tyler

Classifications

• H01Q1/00

  Details of, or arrangements associated with, antennas (arrangements for varying orientation of directional pattern H01Q3/00) · CPC title

• H01Q15/0086 Primary

  said selective devices having materials with a synthesized negative refractive index, e.g. metamaterials or left-handed materials · CPC title

• H01Q15/02

  Refracting or diffracting devices, e.g. lens, prism · CPC title