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: 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: Systems and methods for facilitating substantially uniform dielectric heating capacities. In one aspect, a microwave device comprises a microwave power source and a microwave cavity. The microwave cavity comprises a plurality of surfaces, an empty domain, and a feed connected to the microwave power source for receiving microwave energy from the microwave power source to create a microwave field distribution within the microwave cavity. The microwave device also comprises a plurality of electromagnetic metamaterial layers disposed at different orientations with respect to a surface of the microwave cavity. The plurality of electromagnetic metamaterial layers affect the microwave field distribution and forming a substantially spatially uniform, time-averaged electric field intensity throughout the empty domain of the microwave cavity from the microwave energy.

Abstract: Empirically modulated antenna systems and related methods are disclosed herein. An empirically modulated antenna system includes an antenna and a controller programmed to control the antenna. The antenna includes a plurality of discrete scattering elements arranged in a one- or two-dimensional arrangement. A method includes modulating operational states of at least a portion of a plurality of discrete scattering elements of the antenna in a plurality of different modulation patterns. The plurality of different modulation patterns includes different permutations of the discrete scattering elements operating in different operational states. The method also includes evaluating a performance parameter of the antenna responsive to the plurality of different empirical one- or two-dimensional modulation patterns. The method further includes operating the antenna in one of the plurality of different one- or two-dimensional empirical modulation patterns selected based, at least in part, on the performance parameter.

Abstract: Embodiments disclosed herein relate to a garment system including at least one sensor and at least one actuator that operates responsive to sensing feedback from the at least one sensor to cause a flexible compression garment to selectively constrict or selectively dilate, thereby compressing or relieving compression against at least one body part of a subject. Such selective constriction or dilation can improve muscle functioning or joint functioning during use of motion-conducive equipment, such as an exercise bike or rowing machine.

Abstract: The present disclosure provides systems and methods associated with mode conversion for ultrasound and acoustic radiation devices. A method is disclosed for manufacturing a mode converting structure comprising a holographic metamaterial that, when positioned relative to an acoustic radiation device (AR), modifies an acoustic field profile of the AR device from an input mode to an output mode, the method including identifying a volumetric distribution of acoustic material properties within the mode converting structure to transform an input pressure field distribution of acoustic radiation in the input mode to an output field distribution of acoustic radiation that approximates the target radiation pattern in the output mode and manufacturing the mode converting structure using the identified volumetric distribution of acoustic material properties.

Abstract: A microwave device includes a microwave cavity, a frame, and a window having an electrically insulating substrate and a structure of metallic wires supported by the substrate. The frame defines a perimeter of an opening in the microwave cavity and the frame is conductive and grounded. The window spans the opening and is arranged to reflect RF radiation back into the cavity and to shield the outside of the microwave cavity from RF radiation. The window is optically transparent. Each metallic wire of the structure is electrically connected to the frame and the width of each metallic wire is between 100 nanometres and 30 micrometres.

Abstract: The present technology pertains to a system and method of operation of a metamaterial phase shifter having various use applications. In one aspect of the present disclosure, a phase shifter includes a network of tunable impedance elements and a controller. The controller is coupled to the network of tunable impedance elements and configured to receive a phase shift input value and determine a corresponding tuning voltage to be supplied to each tunable impedance element of the network of tunable impedance elements based on the phase shift input value, the network of tunable impedance element being configured to shift a phase of an input signal based on tuning voltages supplied to the network of tunable impedance elements by the controller.

Abstract: Empirically modulated antenna systems and related methods are disclosed herein. An empirically modulated antenna system includes an antenna and a controller programmed to control the antenna. The antenna includes a plurality of discrete scattering elements arranged in a one- or two-dimensional arrangement. A method includes modulating operational states of at least a portion of a plurality of discrete scattering elements of the antenna in a plurality of different modulation patterns. The plurality of different modulation patterns includes different permutations of the discrete scattering elements operating in different operational states. The method also includes evaluating a performance parameter of the antenna responsive to the plurality of different empirical one- or two-dimensional modulation patterns. The method further includes operating the antenna in one of the plurality of different one- or two-dimensional empirical modulation patterns selected based, at least in part, on the performance parameter.

Abstract: System and methods are described herein for providing wireless power to a target device, such as a laptop computer, a mobile phone, a vehicle, robot, or an unmanned aerial vehicle or system (UAV) or (UAS). A tunable multi-element transmitter may transmit electromagnetic radiation (EMR) to the target device using any of a wide variety of frequency bands. A location determination subsystem and/or range determination subsystem may determine a relative location, orientation, and/or rotation of the target device. For a target device within a distance range for which a smallest achievable waist of the Gaussian beam of the EMR at an operational frequency is smaller than the multi-element EMR receiver of the target device, a non-Gaussian beamform may be determined to increase efficiency, decrease overheating, reduce spillover, increase total power output of rectenna receivers on the target device, or achieve another target power delivery goal.

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: Empirically modulated antenna systems and related methods are disclosed herein. An empirically modulated antenna system includes an antenna and a controller programmed to control the antenna. The antenna includes a plurality of discrete scattering elements arranged in a one- or two-dimensional arrangement. A method includes modulating operational states of at least a portion of a plurality of discrete scattering elements of the antenna in a plurality of different modulation patterns. The plurality of different modulation patterns includes different permutations of the discrete scattering elements operating in different operational states. The method also includes evaluating a performance parameter of the antenna responsive to the plurality of different empirical one- or two-dimensional modulation patterns. The method further includes operating the antenna in one of the plurality of different one- or two-dimensional empirical modulation patterns selected based, at least in part, on the performance parameter.

Abstract: According to various embodiments, systems and methods for transmitting acoustic waves in a region aided by reflection from environmental objects. An arrangement of acoustically reflective surfaces in an environment of a target can be detected to generate an environmental acoustic propagation channel model. An acoustic radiation pattern for reflecting one or more acoustic waves off of one or more acoustically reflective surfaces in the arrangement of acoustically reflective surfaces towards the target can be identified. A coherent acoustic beamforming device can be controlled to perform coherent beamforming of an acoustic hologram based on the acoustic radiation pattern to generate the one or more acoustic waves for reflection towards the target off of the one or more acoustically reflective surfaces.

Abstract: A multi-layer optical device may include one, two, or three layers. A first layer may include an array of Fourier-transforming optically transmissive elements to map optical radiation between each of a plurality of angles of incidence and corresponding coordinate locations proximate each respective optically transmissive element. A second layer may provide a modulation matrix of optically modulating sub-elements optically coupled to the array of transmissive elements, where each optically modulating sub-element corresponds to one of the coordinate locations of the first layer mapping. A third layer includes an array of inverse Fourier-transforming optically transmissive elements to inverse-map optical radiation from the optically modulating sub-elements of the modulation matrix for propagation at angles corresponding to the angles of incidence from which the optical radiation was received.

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

Abstract: The present technology pertains to a system and method of operation of a metamaterial phase shifter having various use applications. In one aspect of the present disclosure, a phase shifter includes a network of tunable impedance elements and a controller. The controller is coupled to the network of tunable impedance elements and configured to receive a phase shift input value and determine a corresponding tuning voltage to be supplied to each tunable impedance element of the network of tunable impedance elements based on the phase shift input value, the network of tunable impedance element being configured to shift a phase of an input signal based on tuning voltages supplied to the network of tunable impedance elements by the controller.

Abstract: In one embodiment, a signal transduction system includes an arrangement of interacting unit cells. Each unit cell can have one or more adjustable parameters that are adjustable to enable one or more adjustable impedance values of the unit cells at each of one or more operational frequencies. The interactions of the unit cells within the arrangement of the interacting unit cells can be describable with an interaction matrix that is approximately independent of the adjustable impedance values of the unit cells.

Abstract: An apparatus is provided for transmission of acoustic signals between a transmitter and a receiver. The apparatus includes an electrical signal generator for generating low frequency electrical signals. The apparatus also includes a transmitter comprising a first retroreflector having a first array of subwavelength retroreflective elements at one end of an open cavity for transmitting the low frequency electrical signals and a first electroacoustic transducer adjacent to the first retroreflector for converting the low frequency electrical signals to acoustic signals. The apparatus further includes a receiver comprising a second retroreflector having a second array of subwavelength retroreflective elements at an opposite end of the open cavity, the acoustic signals being in form of a beam directed toward the receiver.

Abstract: An apparatus is provided for transmission of RF signals between a transmitter and a receiver. The apparatus includes a transmitter comprising a first retroreflector having a first array of sub-wavelength retroreflective elements at one end of an open cavity for transmitting RF seed signals. The apparatus also includes a receiver comprising a second retroreflector having a second array of sub-wavelength retroreflective elements at an opposite end of the open cavity for receiving the transmitted seed signal, the transmitted RF seed signals being in form of a beam directed toward the receiver.

Abstract: Described embodiments include a system and method. A system includes a tracking circuit configured to determine a location of a target device within a Fresnel region of an electronically reconfigurable beam-forming antenna. The antenna is configured to implement at least two selectable focused electromagnetic beams within its Fresnel region. The system includes a beam selector circuit configured to select from the at least two selectable focused electromagnetic beams a focused electromagnetic beam having a focal spot that covers at least a portion of the determined location of the target device. The system includes a beam definition circuit configured to determine an electromagnetic field distribution over an aperture of the electronically reconfigurable beam-forming antenna implementing the selected focused electromagnetic beam. The system includes an output circuit configured to transmit a signal indicative of the determined electromagnetic field distribution.