U.S. Patent No. 10,027,033, for “Wideband electromagnetic cloaking systems,” was granted to three inventors from Fractal Antenna Systems (FAS). The invention leverages expertise in fractal resonator metamaterials to achieve invisibility or optical cloaking.
The cloaks slip-stream or pass electromagnetic waves around an object or obstacle, which is different than optical lens cloaking. Optical lens cloaking can be achieved with a bulky system of special lenses, as shown in this demonstration video from the University of Rochester. FAS first cloaked a man in August 2012 at the Microwaves conference.
Metamaterials can provide a negative index of refraction, negative permeability and negative permittivity. The metamaterial described in the invention uses a fractal or aperiodic arrangement of resonators on the surface of a paper-thin film. The fractal resonators provide an effective electromagnetic lens or back lensing action over certain frequencies, resulting in invisibility. Operation at other frequencies, including those of visible light, infrared, ultraviolet and microwave radiation (e.g., K, Ka, X-bands) may be realized by appropriately scaling dimensions and careful selection of the shapes of the resonator elements. The cloaks could be useful in hiding military vehicles, missiles, aircraft or drones from radar detection.To read more, click here.