Method and system with fragmented metastructures formed with a plurality of metasurface arrays
AssigneeGeorgia Tech Research Corporation
InventorsKenneth Wayne Allen, Daniel J.P. Dykes, David W. Landgren, Christopher Peterson, David R. Reid
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Abstract
An exemplary method and system are disclosed comprising retroreflective metastructures formed with a plurality of metasurface arrays configured to destructively cancel or interfere, in part, with one another to reduce specular mode associated scattering or reflection. In some embodiments, the retroreflective metastructures are formed by a combination of metasurfaces with different lattice spacings that can exhibit enhanced bandwidth and angular range at near-grazing angles to provide enhanced retroreflective electromagnetic responses.
Claims20
An apparatus comprising:
- a substrate defining a top layer of the apparatus, the substrate comprising a retroreflective metasurface comprising a plurality of unit cells defining a macro-pattern, each unit cell comprising two or more types of pixelated-array metasurfaces that define a sub-pattern within the respective unit cell, including a first pixelated-array metasurface and a second pixelated-array metasurface, the first pixelated-array metasurface and the second pixelated-array metasurface being configured to reflect a signal wavefront at a pre-defined range of angle of incidence to generate a scattered wavefront having a resulting first scattered wavefront portion and a second scattered wavefront portion that destructively cancel or interfere, in part, of one another to reduce specular mode of the scattered wavefront,
- wherein the first pixelated-array metasurface has a first pattern having a first associated periodicity, and
- wherein the second pixelated-array metasurface has a second pattern having a second associated periodicity;
- and
- a ground plane coupled to the substrate and defining a bottom layer of the apparatus, the ground plane having a reflective surface to the signal wavefront,
- wherein the top layer is transparent to a first frequency and retroreflective to a second frequency, and wherein the bottom layer functions at the second frequency and is retroreflective to the first frequency.
A system comprising:
- an apparatus, the apparatus comprising:
- a substrate defining a top layer of the apparatus, the substrate comprising a retroreflective metasurface comprising a plurality of unit cells defining a macro-pattern, each unit cell comprising two or more types of pixelated-array metasurfaces that define a sub-pattern within the respective unit cell, including a first pixelated-array metasurface and a second pixelated-array metasurface, the first pixelated-array metasurface and the second pixelated-array metasurface being configured to reflect a signal wavefront at a pre-defined range of angle of incidence to generate a scattered wavefront having a resulting first scattered wavefront portion and a second scattered wavefront portion that destructively cancel or interfere, in part, of one another to reduce specular mode of the scattered wavefront,
- wherein the first pixelated-array metasurface has a first pattern having a first associated periodicity, and
- wherein the second pixelated-array metasurface has a second pattern having a second associated periodicity;
- and
- a ground plane coupled to the substrate and defining a bottom layer of the apparatus, the ground plane having a reflective surface to the signal wavefront, wherein the top layer is transparent to a first frequency and retroreflective to a second frequency, and wherein the bottom layer functions at the second frequency and retroreflective to the first frequency;
- and
- a controller configured to interrogate the apparatus.
Dependencies are inferred from the claim text.