Abstract: A determined object wave can be approximately formed by applying a modulation pattern to metamaterial elements receiving RF energy from a feed network. For example, a desired object wave at a surface of an antenna is selected to be propagated into a far-field pattern. A computing system can compute an approximation of the object wave by calculating a modulation pattern to apply to metamaterial elements receiving RF energy from a feed network. The approximation can be due to a grid size of the metamaterial elements. Once the modulation pattern is determined, it can be applied to the metamaterial elements and the RF energy can be provided in the feed network, causing emission of the approximated object wave from the antenna.

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: Garment systems including a flexible compression garment, at least one sensor, and at least one therapeutic stimulation delivery device operable responsive to sensing feedback from the at least one sensor, effective to provide therapeutic radiation to a body part of a subject. Methods of using such garment systems are also described.

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: 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: 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.

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: Systems and methods are provided for various tunable multi-timescale wireless rectification systems. Tunable multi-timescale wireless rectification systems may include multiple feedback control loops, systems, or sub-systems that modify characteristics of components of a wireless rectification system on various timescales. A wireless rectification system may include antennas, impedance-matching components, rectifying devices, DC-to-DC converters, and/or load controllers. Two or more feedback controls may function on different timescales to modify one or more characteristics or functionalities of components of the wireless rectification system in response to monitored AC and/or DC power values at various locations within the wireless rectification system. Feedback controls operating on various timescales may include antenna feedback controls, impedance feedback controls, rectifying feedback controls, and/or DC feedback controls.

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: Holographic beamforming antennas may be utilized for adaptive routing within communications networks, such as wireless backhaul networks. Holographic beamforming antennas may be further utilized for discovering and/or addressing nodes in a communication network with steerable, high-directivity beams. Holographic beamforming antennas may be further utilized for extending the range of communications nodes and providing bandwidth assistance to adjacent nodes via dynamic adjacent cell assist. In some approaches, MIMO is used in concert with holographic beamforming for additional channel capacity.

Abstract: The present disclosure provides systems and methods associated with mode conversion for ultrasound and acoustic radiation devices. A mode converting structure (holographic metamaterial) is formed with a distribution of acoustic material properties selected to convert an acoustic pressure pattern from a first mode to a second mode to attain a target radiation pattern that is different from the input radiation pattern. A solution to a holographic equation provides a sufficiently accurate approximation of a distribution of acoustic material properties to form a mode converting device. One or more optimization algorithms can be used to improve the efficiency of the mode conversion and generation of the acoustic mode converter.

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: Holographic beamforming antennas may be utilized for adaptive routing within communications networks, such as wireless backhaul networks. Holographic beamforming antennas may be further utilized for discovering and/or addressing nodes in a communication network with steerable, high-directivity beams. Holographic beamforming antennas may be further utilized for extending the range of communications nodes and providing bandwidth assistance to adjacent nodes via dynamic adjacent cell assist. In some approaches, MIMO is used in concert with holographic beamforming for additional channel capacity.

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: A holographic radar reflector includes a surface with a plurality of substantially microwave wavelength scale patterns along one or more portions of the surface. The holographic radar reflector can be a non-specular reflector, where the plurality of substantially microwave wavelength scale patterns have varying reflectivity. The holographic radar reflector can reflect electromagnetic radiation emitted from a fixed feed point in varying directions depending on the portion of the surface reflecting the electromagnetic radiation.

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: 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: 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: The present disclosure provides a system and methods for mitigating, or reducing, the intermodulation of an adaptive antenna array's radiating elements. A tunable element or tunable material, such as a phase change material or a state change material, may be used to increase linearity of the RF transmission properties. These phase or state change materials may modify a radiating element's electromagnetic response. In some embodiments, variable couplers may further be added to a system to reduce intermodulation. An adaptive antenna array using the techniques described herein may have all or some of the elements co-located.