Abstract: Systems and methods are disclosed herein for printed cavities for computational microwave imaging and methods or use. According to an aspect, an imaging system includes a printed cavity having a layer having a first surface and a second surface. The printed cavity defines multiple apertures that extend between the first surface and the second surface. The printed cavity also includes a substrate being attached to the first surface of the layer. The substrate is also configured to be fed a guided wave that excites the apertures to produce a radiation pattern for illuminating a scene. The imaging system also include one or more antennas configured to generate a signal for imaging based on the illuminated scene.

Abstract: A MIMO communication system is provided. The system may include a first antenna comprising a first cavity, a first plurality of RF ports for generating a feed wave within the first cavity, and a first plurality of sub-wavelength artificially structured material elements as arranged on a surface of the first cavity as RF radiators. The first antenna is configured to generate a plurality of radiation patterns respectively corresponding to the first plurality of ports. The system may also include a second antenna comprising a second cavity and a second plurality of sub-wavelength artificially structured material elements arranged on a surface of the second cavity.

Abstract: A metasurface antenna can be configured to focus a paraxial beam, such as a Gaussian beam, on a target within a Fresnel zone region. The focused beam can be used to wirelessly deliver power to the target.

Abstract: According to various embodiments, systems and methods for suppressing grating lobes in a traveling-wave antenna system are disclosed. An apparatus can include a traveling-wave antenna array comprising a plurality of adjacent traveling-wave antennas. The apparatus also can include a phase diversity feed coupled to the traveling-wave antenna array. The phase diversity feed can be configured to provide phase diverse input to two or more of the plurality of adjacent traveling-wave antennas.

Abstract: Systems and methods are disclosed herein for printed cavities for computational microwave imaging and methods or use. According to an aspect, an imaging system includes a printed cavity having a layer having a first surface and a second surface. The printed cavity defines multiple apertures that extend between the first surface and the second surface. The printed cavity also includes a substrate being attached to the first surface of the layer. The substrate is also configured to be fed a guided wave that excites the apertures to produce a radiation pattern for illuminating a scene. The imaging system also include one or more antennas configured to generate a signal for imaging based on the illuminated scene.

Abstract: According to various embodiments, systems and methods for spatial sampling in proximity to the Nyquist limit in traveling-wave antenna systems are disclosed. An apparatus can include a traveling-wave antenna array comprising a plurality of adjacent traveling-wave antennas that each include a plurality of tunable elements that are spaced at, near, or above a Nyquist limit spacing to form an array of tunable elements. The apparatus also includes a phase diversity feed coupled to the traveling-wave antenna array that is configured to provide input to the traveling-wave antenna array including phase diverse input to two or more of the plurality of adjacent traveling-wave antennas. Further, the apparatus includes a plurality of grayscale tuning elements configured to tune the plurality of tunable elements along one or more ranges of one or more tuning variables to form one or more specific output radiation patterns through the traveling-wave antenna array based on the input.

Abstract: Modulation patterns for surface scattering antennas provide desired antenna pattern attributes such as reduced side lobes and reduced grating lobes.

Abstract: A method for acquiring body measurement information includes: detecting that a subject is in proximity to a flat-panel imaging device; capturing, via the flat-panel imaging device, a plurality of images; processing the plurality of images to build a three-dimensional model of the subject; calculating one or more body measurements of the subject based on the three-dimensional model; and outputting the one or more body measurements.

Abstract: An apparatus is described that selectively absorbs electromagnetic radiation. The apparatus includes a conducting surface, a dielectric layer formed on the conducting surface, and a plurality of conducting particles distributed on the dielectric layer. The dielectric layer can be formed from a material and a thickness selected to yield a specific absorption spectrum. Alternatively, the thickness or dielectric value of the material can change in response to an external stimulus, thereby changing the absorption spectrum.

Abstract: A coating for mitigating metal whiskers on a metal surface includes a polymeric coating material; and a metal ion complexing agent impregnated within the polymeric coating material, the metal ion complexing agent having a standard reduction potential) (E°) that is greater than a metal in the metal surface.

Abstract: A MIMO communication system is provided. The system may include a first antenna comprising a first cavity, a first plurality of RF ports for generating a feed wave within the first cavity, and a first plurality of sub-wavelength artificially structured material elements as arranged on a surface of the first cavity as RF radiators. The first antenna is configured to generate a plurality of radiation patterns respectively corresponding to the first plurality of ports. The system may also include a second antenna comprising a second cavity and a second plurality of sub-wavelength artificially structured material elements arranged on a surface of the second cavity.

Abstract: A coating for mitigating metal whiskers on a metal surface includes a polymeric coating material; and a metal ion complexing agent impregnated within the polymeric coating material, the metal ion complexing agent having a standard reduction potential (E°) that is greater than a metal in the metal surface.

Abstract: According to various embodiments, an array of elements forms an artificially-structured material. The artificially-structured material can also include an array of tuning mechanisms included as part of the array of elements that are configured to change material properties of the artificially-structured material on a per-element basis. The tuning mechanisms can change the material properties of the artificially-structured material by changing operational properties of the elements in the array of elements on a per-element basis based on one or a combination of stimuli detected by sensors included in the array of tuning mechanisms, programmable circuit modules included as part of the array of tuning mechanisms, data stored at individual data stores included as part of the array of tuning mechanisms, and communications transmitted through interconnects included as part of the array of elements.

Abstract: The present disclosure provides systems and methods associated with mode conversion for electromagnetic field modification. A mode converting structure (holographic metamaterial) is formed with a distribution of dielectric constants chosen to convert an electromagnetic radiation pattern from a first mode to a second mode to attain a target electromagnetic radiation pattern that is different from the input electromagnetic radiation pattern. A solution to a holographic equation provides a sufficiently accurate approximation of a distribution of dielectric constants that can be used to form a mode converting device for use with one or more transmission lines, such as waveguides. One or more optimization algorithms can be used to improve the efficiency of the mode conversion.

Abstract: An apparatus includes a base having a first surface and an array of pillars. Each pillar of the array of pillars includes (i) a first end attached to the first surface of the base; (ii) a second end having an electric charge retention portion; (iii) a physical separation from adjacent pillars of the array of pillars; and (iv) an electrical conductor configured to electrically connect the electric charge retention portion with a bus structure. The bus structure is configured to addressably connect with the electrical conductor of each respective pillar of the array of pillars.

Abstract: According to various embodiments, an array of elements forms an artificially-structured material. The artificially-structured material can also include an array of tuning mechanisms included as part of the array of elements that are configured to change material properties of the artificially-structured material on a per-element basis. The tuning mechanisms can change the material properties of the artificially-structured material by changing operational properties of the elements in the array of elements on a per-element basis based on one or a combination of stimuli detected by sensors included in the array of tuning mechanisms, programmable circuit modules included as part of the array of tuning mechanisms, data stored at individual data stores included as part of the array of tuning mechanisms, and communications transmitted through interconnects included as part of the array of elements.

Abstract: Surface scattering antennas with lumped elements provide adjustable radiation fields by adjustably coupling scattering elements along a wave-propagating structure. In some approaches, the surface scattering antenna is a multi-layer printed circuit board assembly, and the lumped elements are surface-mount components placed on an upper surface of the printed circuit board assembly. In some approaches, the scattering elements are adjusted by adjusting bias voltages for the lumped elements. In some approaches, the lumped elements include diodes or transistors.

Abstract: A method for facilitating physiological data acquisition includes scheduling a medical appointment between a patient and a medical provider. The medical appointment is to be conducted at a medical provider location on an appointment date. The method also includes selecting a medical device configured to acquire physiological data regarding the patient. The method further includes sending, to a fulfillment system, a request to provide the medical device to a patient location prior to the appointment date. The patient location is remote from the medical provider location.

Abstract: Nanopatch antennas and related methods for enhancing and tailoring are disclosed. According to an aspect, an apparatus includes a conductive material defining a substantially planar surface. The apparatus also includes a conductive nanostructure defining a substantially planar surface. The conductive material and the conductive nanostructure are positioned such that the planar surface of the conductive material faces the planar surface of the conductive nanostructure, such that the planar surfaces are substantially parallel, and such that the planar surfaces are spaced by a selected distance. The apparatus also includes an optically-active material positioned between the planar surfaces.

Abstract: Described embodiments include a system, method, and apparatus. The apparatus includes a magnetic substrate at least partially covered by a first negative-permittivity layer comprising a first plasmonic outer surface. The apparatus includes a plasmonic nanoparticle having a magnetic element at least partially covered by a second negative-permittivity layer comprising a second plasmonic outer surface. The apparatus includes a dielectric-filled gap between the first plasmonic outer surface and the second outer surface. The first plasmonic outer surface, the dielectric-filled gap, and the second plasmonic outer surface are configured to support one or more mutually coupled plasmonic excitations.