Negative-Refraction Metamaterials Using Continuous Metallic Grids Over Ground for Controlling and Guiding Electromagnetic Radiation

• US 20080204164A1
• Filed: 08/09/2005
• Published: 08/28/2008
• Est. Priority Date: 08/09/2004
• Status: Active Grant

• Current Assignee: Ontario Centres of Excellence, Inc. (Province of Ontario)
• Original Assignee: Ontario Centres of Excellence, Inc. (Province of Ontario)
• Inventors: Eleftheriades, George V.
• Granted Patent: US 7,777,594 B2
• Time in Patent Office: Days
• US Class Current: 333/134
• CPC Class Codes: H01Q 15/006 Selective devices having photonic band gap materials or materials of which the material properties are frequency dependent, e.g. perforated substrates, high-impedance surfaces
• CPC Class Codes: H01Q 15/0086 said selective devices having materials with a synthesized negative refractive index, e.g. metamaterials or left-handed materials

Abstract

For the cost effective implementation of negative-index refraction, an anisotropic hyperbolic planar metamaterial comprising a first set of substantially parallel, unloaded and coplanar transmission lines, said first set being spaced with a periodicity dy a second set of substantially parallel, unloaded and coplanar transmission lines, said second set being spaced with a periodicity dx, further being coplanar and substantially orthogonal with said first set of transmission lines, wherein the periodicities of said first set and second set of transmission lines being governed by the relationship βx(fr)dx+βy(fr)dy=2π, where: βx and βy are the intrinsic propagation constants of electromagnetic waves of frequency fr propagating along the first and second set of transmission lines, respectively.

Claims

1. An anisotropic hyperbolic planar metamaterial comprising:

a first set of substantially parallel, unloaded and coplanar transmission lines, said first set being spaced with a periodicity d_y;

a second set of substantially parallel, unloaded and coplanar transmission lines, said second set being spaced with a periodicity d_x, farther being coplanar and substantially orthogonal with said first set of transmission lines, wherein the periodicities of said first set and second set of transmission lines being governed by the relationship;

β

_x(f_r)d_x+β

_y(f_r)d_y=2π

,

where;

β

_x and β

_y are the intrinsic propagation constants of electromagnetic waves of frequency f_r propagating along the first and second set of transmission lines, respectively.

3. A material comprising a plurality of anisotropic hyperbolic planar metamaterials according to claim 1 wherein for at least two said metamaterials, those two said metamaterials have interchanged periodicities in the x and y directions.

4. A method of refracting electromagnetic waves by employing a metamaterial according to claim 1.

5. A method of resonance cone focusing electromagnetic waves by employing a metamaterial according to claim 1.

6. The metamaterial of claim 1 wherein said transmission lines are fabricated using microstrip technology.

7. The metamaterial of claim 6 wherein combined conductor losses and dielectric losses are minimized by selecting an optimum transmission line width corresponding to substrate thickness.

8. The metamaterial of claim 1 wherein said metamaterial supports rectangular dispersion of electromagnetic waves of at least one frequency f_π

where f_π

is not equal to f_r.

9. A harmonic splitter comprising:

at least two metamaterials according to claim 8 having mutually transposed periodicities and joined at an interface,

an input port located at a corner of a first of said metamaterials which is opposite said interface, and

two output ports at both corners of a second of said metamaterials which are opposite said interface.

10. A diplexer comprising:

a splitter metamaterial and at least a first and second tuner metamaterials, each according to claim 1,

wherein the product of periodicity and intrinsic propagation constant of the tuner metamaterials is mutually transposed with respect to the splitter metamaterial, and

wherein the first and second tuner metamaterials have periodicities that support different resonant frequencies.

2. An isotropic planar metamaterial comprising:

a first set of substantially parallel, unloaded and coplanar transmission lines, being spaced with a periodicity d;

a second set of substantially parallel, unloaded and coplanar said transmission lines, being spaced with a periodicity d, said second set of transmission lines being coplanar and substantially orthogonal with said first set of transmission lines, the periodicity of said first set and second set of transmission lines being governed by the relationships;

d=λ

−

δ and

β

=2π

/λ

where;

β

is the intrinsic propagation constant of electromagnetic waves of wavelengths λ

on the transmission lines and δ

is a differential length such that 6<

k/2.