Ultradirective antenna via transformation optics

Spatial coordinate transformation is used as a reliable tool to control electromagnetic fields. In this paper, we derive the permeability and permittivity tensors of a metamaterial able to transform an isotropically radiating source into a compact ultradirective antenna in the microwave domain. We show that the directivity of this antenna is competitive with regard to conventional directive antennas (horn and reflector antennas), besides its dimensions are smaller. Numerical simulations using finite element method are performed to illustrate these properties. A reduction in the electromagnetic material parameters is also proposed for an easy fabrication of this antenna from existing materials. Following that, the design of the proposed antenna using a layered metamaterial is presented. The different layers are all composed of homogeneous and uniaxial anisotropic metamaterials, which can be obtained from simple metal-dielectric structures. When the radiating source is embedded in the layered metamaterial, ...

[1]  J. Huangfu,et al.  Planar focusing antenna design by using coordinate transformation technology , 2007 .

[2]  Huanyang Chen,et al.  Transformation media that rotate electromagnetic fields , 2007, physics/0702050.

[3]  Stewart,et al.  Extremely low frequency plasmons in metallic mesostructures. , 1996, Physical review letters.

[4]  David R. Smith,et al.  Optical design of reflectionless complex media by finite embedded coordinate transformations. , 2007, Physical review letters.

[5]  J. Huangfu,et al.  Application of coordinate transformation in bent waveguides , 2008 .

[6]  David R. Smith,et al.  Metamaterial Electromagnetic Cloak at Microwave Frequencies , 2006, Science.

[7]  David R. Smith,et al.  Controlling Electromagnetic Fields , 2006, Science.

[8]  U. Leonhardt.  Optical Conformal Mapping , 2006, Science.

[9]  David R. Smith,et al.  Design of electromagnetic cloaks and concentrators using form-invariant coordinate transformations of Maxwell’s equations , 2007, 0706.2452.

[10]  G. Uhlmann,et al.  Electromagnetic wormholes and virtual magnetic monopoles from metamaterials. , 2007, Physical review letters.

[11]  J. Pendry,et al.  Transformation-optical design of adaptive beam bends and beam expanders. , 2008, Optics express.

[12]  Xiangang Luo,et al.  Design of electromagnetic refractor and phase transformer using coordinate transformation theory. , 2008, Optics express.

[13]  J. Pendry,et al.  Calculation of material properties and ray tracing in transformation media. , 2006, Optics express.

[14]  T. Cui,et al.  Layered high-gain lens antennas via discrete optical transformation , 2008 .

[15]  Constantine A. Balanis,et al.  Antenna Theory: Analysis and Design , 1982 .

[16]  J. Lourtioz,et al.  Infrared cloaking based on the electric response of split ring resonators. , 2008, Optics express.