Aspect of the present disclosure are directed to methods and apparatus producing enhanced radiation characteristics, e.g., wideband behavior, in or for antennas and related components by providing concentric sleeves, with air or dielectric material as a spacer, where the sleeves include one or more conductive layers, at least a portion of which includes fractal resonators closely spaced, in terms of wavelength. A further aspect of the present disclosure is directed to surfaces that include dual-use or multiple-use apertures. Such aperture engine surfaces can include a first layer of antenna arrays, a second layer including a metal-fractal backplane player, and a third layer including solar cells for solar cell or solar oriented power collection. Fractal metamaterial ribbons with multiple closely-packed fractal resonators are also disclosed.

Arrangement of resonators in an aperiodic configurations are described, which can be used for electromagnetic cloaking of objects. The overall assembly of resonators, as structures, do not all repeat periodically and at least some of the resonators are spaced such that their phase centers are separated by more than a wavelength. The arrangements can include resonators of several different sizes and/or geometries arranged so that each size or geometry corresponds to a moderate or high Q response that resonates within a specific frequency range, and that arrangement within that specific grouping of akin elements is periodic in the overall structure. The relative spacing and arrangement of groupings can be defined by self similarity and origin symmetry. Fractal based scatters are described. Further described are bondary condition layer structures that can activate and deactive cloaking/lensing structures.

Antenna systems are described which provide means of mitigating the undesirable transmission line effect(s) by using fractal metamaterials in close proximity to an antenna, with both the antenna and fractal metamaterials being positioned a conductive surface, which may be inside or adjacent to a cavity. The fractal metamaterial can include an array of close spaced (e.g., less than 1/10 wavelength separation) resonant structures of a fractal shape, resonant at or near the intended frequency of use of the antenna. The fractal metamaterial can reverse the phase of the reflected wave so that the metal cavity no longer produces an out of phase current induced by the antenna. Without the cavity being out of phase to the antenna, the transmission line effect is mitigated substantially and the antenna performance can accordingly be enhanced. Further embodiments omit a cavity and locate a fractal metamaterial and antenna(s) adjacent to an underlying conductive surface.

Novel directional antennas are disclosed which utilize plasmonic surfaces (PS) that include or present an array of closely-spaced parasitic antennas, which may be referred to herein as parasitic arrays or fractal plasmonic arrays (FPAs). These plasmonic surfaces represent improved parasitic directional antennas relative to prior techniques and apparatus. Substrates can be used which are transparent and/or translucent.

Disclosed is a vehicular antenna, which includes an antenna module having an antenna patch, a reflector installed to be spaced apart from the antenna patch by a predetermined distance to maximize a gain of an electromagnetic wave radiated from the antenna patch at a specific angle, and a dielectric substance inserted and installed between the antenna patch and the reflector.

Resonant frequency stability of passbands or stopbands is provided over varying incidence angles and polarizations in a dual band frequency selective surface (FSS) device. The FSS device comprises an array of fractal unit cells. The fractal elements may comprise single fractal, or double fractal, or convoluted, or split ring resonator slot elements printed on a thin dielectric substrate. Each cell includes a first fractal pattern and a second fractal pattern which interact to provide the improved performance. In one form, a two-screen fractal FSS is etched on both sides of a thin dielectric substrate. The top FSS screen's unit cell has one fractal loop patch element, while the bottom FSS screen's unit cell has a higher order iteration of the same fractal. In another form, two fractal screens are incorporated in one dielectric layer positioned between two substrate layers. In yet another form, two fractal loop slot element FSSs are provided.

Vivaldi tapered slot and Vivaldi horn antennas that feature or include fractal plasmonic surfaces (FPS) are described. Vivaldi slot antennas are described which include a conductive surface defining a tapered slot, with the conductive surface including a plurality of fractal resonators which form or constitute a fractal plasmonic surface (FPS). In some embodiments the fractal resonators can be defined by slots. In some embodiments the fractal resonators can include self-complementary features. In exemplary embodiments, two Vivaldi horn antennas may be used for a Vivaldi horn antenna. The two Vivaldi FPS antennas can be arranged in a crossed or cross configuration such that the two antennas are essentially perpendicular to one another and are therefore able to receive and transmit two orthogonal polarizations of radiation. The two antennas can be fed by separate respective feed lines. The two antennas can be mounted inside of a horn or casing.

Aspect of the present disclosure are directed to methods and apparatus producing enhanced radiation characteristics, e.g., wideband behavior, in or for antennas and related components by providing concentric sleeves, with air or dielectric material as a spacer, where the sleeves include one or more conductive layers, at least a portion of which includes fractal resonators closely spaced, in terms of wavelength. A further aspect of the present disclosure is directed to surfaces that include dual-use or multiple-use apertures. Such aperture engine surfaces can include a first layer of antenna arrays, a second layer including a metal-fractal backplane player, and a third layer including solar cells for solar cell or solar oriented power collection. Fractal metamaterial ribbons with multiple closely-packed fractal resonators are also disclosed.

A multi-polarized continuous transverse stub (CTS) antenna includes a first feed network operative to at least one of receive or transmit a signal having a first polarization, and a second feed network different from the first feed network and operative to at least one of receive or transmit a signal having a second polarization different from the first polarization. At least one parallel-plate region is defined by a first plate structure and a second plate structure spaced apart from the first plate structure, where a first coupling structure connecting the first feed network to the parallel-plate region and a second coupling structure connecting the second feed network to the parallel-plate region. A common aperture is arranged on one side of the parallel-plate region, wherein wavefronts produced by the first and second coupling structures and propagated within the parallel-plate region radiate to free-space through the common aperture.

Aspect of the present disclosure are directed to methods and apparatus producing enhanced radiation characteristics, e.g., wideband behavior, in or for antennas and related components by providing concentric sleeves, with air or dielectric material as a spacer, where the sleeves include one or more conductive layers, at least a portion of which includes fractal resonators closely spaced, in terms of wavelength. A further aspect of the present disclosure is directed to surfaces that include dual-use or multiple-use apertures. Such aperture engine surfaces can include a first layer of antenna arrays, a second layer including a metal-fractal backplane player, and a third layer including solar cells for solar cell or solar oriented power collection. Fractal metamaterial ribbons with multiple closely-packed fractal resonators are also disclosed.