Metamaterials for controlling and guiding electromagnetic radiation and applications therefor

• US 6,859,114 B2
• Filed: 06/02/2003
• Issued: 02/22/2005
• Est. Priority Date: 05/31/2002
• Status: Expired due to Fees

• Current Assignee: George V. Eleftheriades, Keith G. Balmain
• Original Assignee: George V. Eleftheriades, Keith G. Balmain
• Inventors: Eleftheriades, George V., Balmain, Keith G.
• Primary Examiner(s): Young, Brian
• Assistant Examiner(s): LAUTURE, JOSEPH J
• Application Number:
  US10/453,907
• Publication Number:
  US 20040066251A1
• Time in Patent Office: 631 Days
• Field of Search: 333/156, 333/116, 333/204, 343/700
• US Class Current: 333/156
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: G02B 1/007 made of negative effective refractive index materials
• CPC Class Codes: H01P 1/18 Phase-shifters H01P1/165 takes precedence
• CPC Class Codes: H01P 3/00 Waveguides; Transmission lines of the waveguide type
• CPC Class Codes: H01P 5/227 90° branch line couplers

Abstract

A linear metamaterial comprises a transmission line, having a linear dimension, and is loaded with capacitors, and shunted with an inductor such that for an electromagnetic wave, having a wavelength greater than the linear dimension and traveling along the axis of the transmission line, the effective permeability and permittivity of the metamaterial are simultaneously negative. Applications for the metameterial are also disclosed.

Claims

1. A planar metamaterial comprising:

two substantially orthogonal, coplanar sets of transmission lines, said transmission lines being spaced with a periodicity, loaded with capacitors with said periodicity, and shunted with inductors with said periodicity such that for an electromagnetic wave having a wavelength greater than said periodicity and traveling along the plane of said transmission lines, an effective permeability and permittivity of said metamaterial are simultaneously negative.

2. A planar metamaterial according to claim 1 wherein the wavelength of said electromagnetic wave is greater than said periodicity by an order of magnitude.

3. A linear metamaterial comprising:

a transmission line, having a linear dimension, and being loaded with capacitors, and shunted with an inductor such that for an electromagnetic wave having a wavelength greater than said linear dimension and traveling along the axis of said transmission line, an effective permeability and permittivity of said metamaterial are simultaneously negative.

4. A planar metamaterial according to claim 3 wherein the wavelength of said electromagnetic wave is greater than said periodicity by an order of magnitude.

5. A metamaterial according to claim 4 wherein the values of said capacitors and inductor are proportioned to provide a continuous passband for said electromagnetic wave.

6. A metamaterial according to claim 4 wherein said transmission line includes two substantially identical capacitors on either side of said inductor.

7. A metamaterial according to claim 4 further comprising a plurality of substantially identical transmission lines arranged in series.

8. A metamaterial according to claim 7 wherein each transmission line includes two substantially identical capacitors on either side of said inductor.

9. A metamaterial according to claim 8 wherein the values of said capacitors and inductor are proportioned to provide a continuous passband for said electromagnetic wave.

10. A planar resonance cone metamaterial comprising:

a first set of transmission lines, spaced with a periodicity, and loaded with capacitors with said periodicity;

a second set of transmission lines, substantially orthogonal and coplanar with said first set of transmission lines, said second set of transmission lines being spaced with said periodicity, and loaded with inductors with said periodicity, said first and second sets of transmission lines exhibiting characteristics such that for an electromagnetic wave having a wavelength greater than said periodicity by an order of magnitude, and traveling along the linear axis of said first set of transmission lines, an effective permittivity of said metamaterial is positive such that for an electromagnetic wave having a wavelength greater than said periodicity by an order of magnitude and traveling along the linear axis of said second set of transmission lines, the effective permittivity of said metamaterial is negative.

11. A metamaterial according to claim 10 further comprising an input on the perimeter of said metamaterial coincident with an intersection of one transmission line of said first set and one transmission line of said second set and a plurality of outputs on the perimeter of said metamaterial coincident with intersections of transmission lines of said first and second sets.

12. A planar resonance cone metamaterial comprising:

a first set of transmission lines, spaced with a first periodicity, and loaded with capacitors with a second periodicity;

a second set of transmission lines, substantially orthogonal and coplanar with said first set of transmission lines, said second set of transmission lines being spaced with said second periodicity, and being loaded with inductors with said first periodicity whereby for an electromagnetic wave having a wavelength greater than said first and second periodicities by an order of magnitude and traveling along the longitudinal axis of said first set of transmission lines, an effective permittivity of said metamaterial is positive and for an electromagnetic wave having a wavelength greater than said first and second priodocities and traveling along the longitudinal axis of said second set of transmission lines, the effective permittivity of said metamaterial is negative.

13. A near field focusing device comprising:

a first set of transmission lines, said first set of transmission lines being spaced with a first periodicity and loaded with capacitors with a second periodicity;

a second set of transmission lines, substantially orthogonal to, and coplanar with said first set of transmission lines, said second set of transmission lines being spaced with said second periodicity, loaded with capacitors with said first periodicity, and shunted with inductors, said first set of transmission lines intersecting said second set of transmission lines such that for an electromagnetic wave having a wavelength greater than said first or second periodicity by an order of magnitude, and traveling along the plane of said transmission lines, an effective permeability and permittivity of said metamaterial are simultaneously negative; and

a planar waveguide having a flat extent, coupled to said transmission lines, such that said flat extent is parallel to one set of transmission lines.

14. A phase-shifting device comprising:

a transmission line, having a linear dimension and characteristic impedance;

capacitors loaded on said transmission line; and

an inductor shunting said transmission line, said transmission line exhibiting characteristics such that for an electromagnetic wave having a wavelength greater than said linear dimension by an order of magnitude and traveling along the axis of said transmission line, an effective permeability and permittivity of transmission are simultaneously negative and such that said transmission line provides a continuous passband for said electromagnetic wave along said transmission line.

15. A phase-shifting device according to claim 14 further comprising a plurality of transmission lines coupled in series.

16. A phase-shifting-device according to claim 15 wherein each transmission line includes a pair of identical capacitors on either side of said inductor.

17. A near field focussing device comprising:

a parallel-plate waveguide; and

a negative refractive index metamaterial in line with said waveguide and forming an interface therewith.

18. A focussing device according to claim 17 wherein said waveguide serves as a right-handed medium, electromagnetic radiation passing through said interface from said waveguide being focussed in said metamaterial.