PLANAR META-MATERIAL HAVING NEGATIVE PERMITTIVITY, NEGATIVE PERMEABILITY, AND NEGATIVE REFRACTIVE INDEX, PLANAR META-MATERIAL STRUCTURE INCLUDING THE PLANAR META-MATERIAL, AND ANTENNA SYSTEM INCLUDING THE PLANAR META-MATERIAL STRUCTURE

• US 20110199273A1
• Filed: 08/12/2009
• Published: 08/18/2011
• Est. Priority Date: 10/27/2008
• Status: Abandoned Application

• Current Assignee: Electronics and Telecommunications Research Institute
• Original Assignee: Electronics and Telecommunications Research Institute
• Inventors: Kim, Dongho, Choi, Jae-Ick, Lee, Wangjoo, Ju, Jeongho
• Application Number:
  US13/126,406
• Publication Number:
  US 20110199273A1
• Time in Patent Office: Days
• US Class Current: 343/753
• CPC Class Codes: G02B 1/002 made of materials engineered to provide properties not available in nature, e.g. metamaterials
• CPC Class Codes: H01Q 15/0086 said selective devices having materials with a synthesized negative refractive index, e.g. metamaterials or left-handed materials
• CPC Class Codes: H01Q 15/02 Refracting or diffracting devices, e.g. lens, prism
• CPC Class Codes: H01Q 21/08 the units being spaced along or adjacent to a rectilinear path waveguide fed H01Q21/0037

Abstract

Provided is a planar meta-material (100) having negative permittivity, negative permeability, and a negative refractive index through a simple structure using a general conductor and a dielectric material (130), a planar meta-material structure including a planar meta-material (100), and a lens realized by using the planar meta-material structure or an antenna system, which has high efficiency and high gain, by including the planar meta-material structure. The planar meta-material includes: a planar dielectric material (130) having a single layer structure with single permittivity or a multilayer structure having at least two permittivities; a first conductor unit (110), which is disposed on a top surface of the planar dielectric material and includes a first conductor (110a, 110b) having a loop shape; and a second conductor unit (120), which is disposed on bottom surface of the planar dielectric material and includes a second conductor (120a, 120b) having the same shape as the first conductor, wherein permittivity, permeability, and a refractive index of the planar meta-material have zero or a negative value in a predetermined frequency domain.

Claims

1. A planar meta-material comprising:

a planar dielectric material having a single layer structure with single permittivity or a multilayer structure having at least two permittivities;

a first conductor unit, which is disposed on a top surface of the planar dielectric material and comprises a first conductor having a loop shape; and

a second conductor unit, which is disposed on a bottom surface of the planar dielectric material and comprises a second conductor having the same shape as the first conductor,

wherein the permittivity, permeability, and refractive index of the planar-meta material have values of 0-1 or a negative value in a predetermined frequency domain.

2. The planar meta-material of claim 1, wherein the planar dielectric material has a rectangular planar structure,

each of the first and second conductors has a rectangular loop shape, and

each of the first and second conductor units comprises an internal conductor having a cross shape disposed within each of the first and second conductor units.

3. The planar meta-material of claim 2, wherein each of the first and second conductors has a square loop shape, wherein each side of the square loop has a first width and maintains a first gap from each side of the planar dielectric material,

the internal conductor has a second width, wherein each end of the cross has the same shape as each vertex of the square loop and maintains a second gap from the side of the square loop, and

the refractive index, impedance, permittivity, and permeability of the planar meta-material changes as at least one parameter from among a length of one side of the square loop, a thickness of the planar dielectric material, the first width, the first gap, the second width, and the second gap changes.

4. The planar meta-material of claim 1, wherein the planar dielectric material has a rectangular planar structure,

each of the first and second conductors has a rectangular loop shape disposed with a predetermined gap from each side of the planar dielectric material, and

has a recessed portion that is recessed in a rectangular shape in the center, and

a via hole is formed on sides of the first and second conductors, which are recessed toward the center of the planar meta-material, wherein the first and second conductors are connected through the via hole.

5. The planar meta-material of claim 4, wherein each of the first and second conductors has a square loop shape, wherein each side of the square loop has a first width and a first gap along each side of the planar dielectric material, each length of two parallel sides of the recessed portion has a first length, wherein the two parallel sides have a second gap, and

the refractive index, impedance, permittivity, and permeability of the planar meta-material changes as at least one parameter from among a length of one side of the square loop, the first width, the first gap, the second gap, and the first length changes.

6. A planar meta-material structure, comprising a plurality of unit cells each composed of the planar meta-material of claim 1, wherein the unit cells are disposed in an array form in rows and columns.

7. The planar meta-material structure of claim 6, wherein each of the unit cells is composed of the planar meta-material of claim 2 or 4.

8. An antenna system comprising:

a lower structure which comprises a ground and a dielectric layer disposed on the ground;

an antenna unit which is disposed on the lower structure and comprises at least one antenna; and

the planar meta-material structure of claim 6 which is disposed on the antenna unit.

9. The antenna system of claim 8, wherein the ground and the planar meta-material structure are spaced apart from each other by a distance that satisfies a resonance condition of a cavity.

10. The antenna system of claim 8, wherein, when a wave proceeds in a Z-axis direction and the antenna unit comprises at least two antennas, the at least two antennas are disposed in an X-axis direction or a Y-axis direction, or in the X-axis direction and the Y-axis direction.

11. The antenna system of claim 8, wherein the ground and the planar meta-material structure are spaced apart from each other by a distance that satisfies a resonance condition of a cavity, and

the antenna unit is spaced apart from each of the lower structure and the planar meta-material structure by a predetermined distance, or is disposed directly on the lower structure.

12. The antenna system of claim 8, wherein the shape of the planar meta-material is changed to adjust a beam width of an emitted wave.

13. The antenna system of claim 8, wherein the planar meta-material structure comprises unit cells each composed of the planar meta-material of claim 2 or 4.

14. A lens for subwavelength imaging, comprising the planar meta-material structure of claim 6.

15. The lens of claim 14, wherein the planar meta-material structure as the lens is disposed in front of and spaced apart by a predetermined distance from a source that emits waves, wherein an image is formed on an image plane disposed in front of the planar meta-material structure.

16. The lens of claim 14, wherein the planar meta-material structure comprises unit cells each composed of the planar meta-material of claim 2 or 4.