Abstract: Spatial light modulators and associated methods are described. In one embodiment, a spatial light modulator includes a photonic integrated circuit configured for emitting a plurality of light beams as a first waveform by a plurality of pixels. The light beams are individually controllable. The spatial light modulator also includes a meta-optic having a plurality of nanostructures configured for receiving the first waveform and aggregating the plurality of light beams as a second waveform at a surface of the meta-optic. The spatial light modulator also includes an aperture array configured for converting the second waveform into a third waveform, where the third waveform is smaller than the second waveform.

Abstract: A system for producing a millimeter wave image of an object, the system including: a storage unit including a material at least partially transparent to millimeter waves and configured to contain the object; a millimeter wave sensor providing millimeter wave data, the sensor including: an array of millimeter wave transmitting antennas; and an array of millimeter wave receiving antennas; one or more processors; and one or more memory devices having stored thereon instructions that when executed by the one or more processors cause the one or more processors to: receive the millimeter wave data from the sensor; generate estimated positions of the millimeter wave sensor relative to the storage unit, wherein the millimeter wave sensor and the storage unit are in relative motion; and process the millimeter wave data and the estimated positions to produce the millimeter wave image of the object.

Abstract: The present application is directed to a video-based motion extraction system that uses mmWave imaging. In one example, an object velocity is extracted in real time from at least one motion vector obtained from a compressed video. The velocity information is combined with distance information obtained from a distance sensor. The combination of distance and velocity is used to calculate a position of the object at each time instance. A velocity profile may be generated. The velocity profile may then be used to reconstruct an image of an object passing in front of an mmWave antenna array.

Abstract: Systems and methods for detecting anomalies in an envelope including scanning an envelope moving along a conveyor with multiple millimeter wave imaging sensor modules and collecting reflection measurements from the sensor modules. The systems and methods can further include constructing a one or more voxel thick horizontal 3D image of the envelope and then creating an image of the envelope comprising the magnitude of the mean of the one or more voxel layers. The image of the envelope can be fed into a binary logistic regression classifier to provide a probability that the envelope contains an anomaly from the classifier. The systems and methods can include causing the envelope to be diverted from the conveyor for further inspection when the probability is greater than a selected threshold.

Abstract: The present application is directed to image beat pattern mitigation in two-sided reflection based 3-D millimeter wave imaging. In one example, active millimeter-wave (mmWave) imaging illuminates a scene with a source of mmWave energy and forms images based on the reflected energy. Two-sided reflection imaging can be used to overcome the occlusion by the opaque objects that would plague a transmission imaging approach. The system can produce beat-pattern-free 3-D images of the products inside an optically-opaque corrugated cardboard shipping box and further, the two-sided reflection imaging approach with image beat pattern correction shows an increased image volume even if portions of the scene are occluded.

Abstract: Examples of active millimeter-wave imaging systems are described which may utilize modulation schemes to provide illumination signals. The use of modulation techniques may allow for the use of direct-conversion receivers while retaining an ability to separate desired received signal from self-jamming and/or DC offset signal(s) generated by the direct-conversion receivers. In some examples, modulation schemes include the use of balanced orthogonal codes which may support MIMO or massive MIMO imaging systems.

Abstract: Examples of digital architectures for OFDM backscatter communication are described herein that use RF switches and discrete loads to implement digitally controlled single-sideband OFDM backscatter devices. One or more transforms may be implemented, including one or more IFFTs, LUTs, and/or numerically-controlled oscillators using one or more sine LUTs.

Abstract: Examples of imaging systems are described herein which may implement microwave or millimeter wave imaging systems. Examples described may implement partitioned inverse techniques which may construct and invert a measurement matrix to be used to provide multiple estimates of reflectivity values associated with a scene. The processing may be partitioned in accordance with a relative position of the antenna system and/or a particular beamwidth of an antenna. Examples described herein may perform an enhanced resolution mode of imaging which may steer beams at multiple angles for each measurement position.

Abstract: Examples of imaging systems are described herein which may implement microwave or millimeter wave imaging systems. Examples described may implement partitioned inverse techniques which may construct and invert a measurement matrix to be used to provide multiple estimates of reflectivity values associated with a scene. The processing may be partitioned in accordance with a relative position of the antenna system and/or a particular beamwidth of an antenna. Examples described herein may perform an enhanced resolution mode of imaging which may steer beams at multiple angles for each measurement position.

Abstract: Examples of active millimeter-wave imaging systems are described which may utilize modulation schemes to provide illumination signals. The use of modulation techniques may allow for the use of direct-conversion receivers while retaining an ability to separate desired received signal from self-jamming and/or DC offset signal(s) generated by the direct-conversion receivers. In some examples, modulation schemes include the use of balanced orthogonal codes which may support MIMO or massive MIMO imaging systems.

Abstract: Systems and methods are described herein for providing wireless power to a mobile device, such as an aerial mobile device like an unmanned aerial vehicle (UAV). A navigational constraint model may prescribe a navigation path along which a wireless power transmission system can provide wireless power to the mobile device. Deviations from the prescribed path may require the mobile device to self-power. The prescription of a navigation path allows for the use of reduced-complexity wireless power transmitters that are fully capable of servicing the prescribed path. Multiple embodiments of prescribed paths with various limitations and features are set forth herein, along with multiple embodiments of wireless power transmission systems of reduced complexity and functionality to fully service the various embodiments of prescribed paths.

Abstract: Examples of active millimeter-wave imaging systems are described which may utilize modulation schemes to provide illumination signals. The use of modulation techniques may allow for the use of direct-conversion receivers while retaining an ability to separate desired received signal from self-jamming and/or DC offset signal(s) generated by the direct-conversion receivers. In some examples, modulation schemes include the use of balanced orthogonal codes which may support MIMO or massive MIMO imaging systems.

Abstract: Examples described herein include devices and methods that may facilitate interoperability between backscatter devices and wireless communication devices. For example, backscatter devices and methods for backscattering are described that provide a transmitted backscattered signal formatted in accordance with a wireless communication protocol (e.g. Bluetooth Low Energy, WiFi, IEEE 802.11, or IEEE 802.15.4). Such communication may reduce or eliminate any modifications required to wireless communication devices necessary to receive and decode backscattered signals.

Abstract: Examples of digital architectures for OFDM backscatter communication are described herein that use RF switches and discrete loads to implement digitally controlled single-sideband OFDM backscatter devices. One or more transforms may be implemented, including one or more IFFTs, LUTs, and/or numerically-controlled oscillators using one or more sine LUTs.

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: An embodiment of an antenna configured to form a high-power beam, such as a battery-charging beam, includes a transmission structure, signal couplers, amplifiers, and antenna elements. The transmission structure (e.g., a waveguide) is configured to carry a reference signal (e.g., a traveling reference wave), and each of the signal couplers is configured to generate a respective intermediate signal in response to the reference signal at a respective location along the transmission structure. Each of the amplifiers is configured to amplify, selectively, an intermediate signal from a respective one of the couplers, and each of the antenna elements (e.g., conductive patches) is configured to radiate a respective elemental signal in response to an amplified intermediate signal from a respective one of the amplifiers. In operation, the elemental signals interfere with one another to form a transmission beam, such as a battery-charging, or other high-power, transmission beam.

Abstract: An embodiment of an antenna array includes a cavity, signal couplers, and antenna elements. The cavity is configured to reinforce a reference signal (e.g., a standing reference wave) having a wavelength ?, and each of the signal couplers is configured to generate a respective intermediate signal in response to the reference signal at a respective location of the cavity. And each of the antenna elements (e.g., conductive patches) is configured to radiate a respective elemental signal in response to an intermediate signal from a respective one of the signal couplers. In operation, the elemental signals interfere with one another to form a transmission beam. Controlling the cavity to introduce phase differences between the antenna elements can allow a wider pitch between adjacent antenna elements without the need for large, costly phase shifters, where the pitch can approach its theoretical limit of approximately ?/2.

Abstract: Examples of imaging systems are described herein which may implement microwave or millimeter wave imaging systems. Examples described may implement partitioned inverse techniques which may construct and invert a measurement matrix to be used to provide multiple estimates of reflectivity values associated with a scene. The processing may be partitioned in accordance with a relative position of the antenna system and/or a particular beamwidth of an antenna. Examples described herein may perform an enhanced resolution mode of imaging which may steer beams at multiple angles for each measurement position.

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: Examples of receivers and receiver techniques are described herein. An example system may include a carrier source that may provide a wireless carrier signal and a wireless communication device, separate from the carrier source. The wireless communication device may provide a wireless communication signal containing data. A receiver may include an antenna positioned to receive the wireless carrier signal and the wireless communication signal, a two-port mixer coupled to the antenna and configured to mix the wireless carrier signal and the wireless communication signal to provide an intermediate frequency signal, and a demodulator configured to extract, at least in part, the data from the intermediate frequency signal.