Metamaterial gradient index lens

Abstract

Examples of the present invention include a gradient index element formed from a material such as a metamaterial, the material having an index profile and an index gradient profile, where the index profile includes at least one discontinuity and the index gradient profile is substantially continuous.

Description

FIELD OF THE INVENTION[0001]The invention relates to gradient index materials, such as gradient index metamaterials, and applications thereof.BACKGROUND OF THE INVENTION[0002]Metamaterials are typically artificially structured composite materials. Components and structural parameters may be selected to obtain electromagnetic properties that are not readily available in a homogeneous material.[0003]The electromagnetic response of metamaterials is discussed in Int. Pub. WO 2006 / 023195 to Smith et al. In some metamaterial examples, permittivity and / or permeability may be negative at the electromagnetic frequency of interest. A metamaterial typically comprises a plurality of unit cells. In typical examples, each unit cell includes an electrically conducting pattern, such as a resonator, for example a split ring resonator, supported on a dielectric substrate. The metamaterial response may be determined from the unit cell parameters. Unit cell parameters include parameters such as resonan...

AI Technical Summary

Benefits of technology

The present invention relates to materials and lenses with a unique index profile that can be controlled at a sub-cellular level. The index profile includes discontinuities, which allows for a more precise control of the index than traditional methods. The lenses have improved properties such as improved radio frequency devices and automotive radar applications. The invention also includes gradient index lenses with a continuous variation in index gradient. The index gradient can be maintained over a larger spatial extent than conventional lenses. The invention can be implemented using metamaterials, which are artificially structured composite materials with an index profile and index gradient.

Problems solved by technology

However, the range of unit cell parameters available may have an effective upper and lower bound, for example due to manufacturing limitations such as physical limits on a size variation.

Such limitations conventionally present a restriction on the index variation possible within a metamaterial, and limit applications of a metamaterial.

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