According to various embodiments, a tunable optical device comprises a tunable optical metasurface on a substrate with an integrated driver circuit. In some embodiments, the tunable optical device includes a photon shield layer to prevent optical radiation from disrupting operation of the driver circuit. In some embodiments, the tunable optical device includes a diagnostic circuit to detect and disable defective optical structures of the metasurface. In some embodiments, the tunable optical device includes an integrated heater circuit that maintains a liquid crystal of the metasurface above a minimum operating temperature. In some embodiments, the tunable optical device includes an integrated lidar sequencing controller, a steering pattern subcircuit, and a photodetector circuit.

The disclosed embodiments relate to the design of a system that implements a reflectarray antenna. The system includes a time-modulated metasurface, which is configured to act as a planar reflector for an electromagnetic wave that is radiated by a feeder into free space at an operation frequency f.sub.0. The time-modulated metasurface includes time-modulated unit-cells that provide a nonlinear conversion between f.sub.0 and another desired frequency f.sub.d. The system also includes a phase-delay mechanism, which adjusts a phase delay by acting on a phase applied to a modulation frequency f.sub.m that modulates each unit-cell. The nonlinear conversion and the phase-delay mechanism operate collectively to facilitate angle-independent nonreciprocity by imposing different phase gradients during up-conversion and down-conversion processes, and by preventing generation of certain propagative harmonics due to total internal reflection.

Synthetic aperture radar transmit and receive antenna systems and methods of transmitting and receiving radar signals are disclosed. In one embodiment, a transmit and receive antenna system includes a transmit antenna array configured to transmit a plurality of radio frequency transmit signals, the transmit antenna array including a plurality of patch antenna elements mounted to a printed circuit board, each patch antenna element belonging to a subarray, and one or more power amplifiers, each power amplifier feeding a subarray of the patch antenna elements, and a reflectarray receive antenna configured to receive radio frequency signals including a plurality of reflectarray antenna elements mounted to a printed circuit board, at least one antenna feed configured to receive radio frequency signals reflected from the plurality of reflectarray antenna elements, and at least one low noise amplifier electrically connected to the at least one antenna feed.

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.

A method for optimizing user equipment wireless localization using K reconfigurable intelligent surfaces reflecting signal(s) transmitted between a base station and the user equipment, the method including, whatever an a priori position of the user equipment selecting at least one reconfigurable intelligent surface to activate among the K reconfigurable intelligent surfaces, determining phases of elements of the at least one reconfigurable intelligent surface, by minimizing a predetermined cost function, depending on the a priori position, and accounting for a predetermined position error bound of the user equipment, while ensuring that at most K reconfigurable intelligent surfaces are selected, ensuring that the minimum Euclidian distance between two consecutive selected reconfigurable intelligent surfaces of a predetermined configuration, is strictly higher than a predetermined value limiting interference between additional multipath components generated by the at least one reconfigurable intelligent surface.

A microwave single pixel imager apparatus and method of using same. Sampling a targeted scene includes the following. A plurality of modulated antenna patterns is generated using a reflectarray. A plurality of antenna temperatures respectively corresponding to the plurality of modulated antenna patterns is measured. A retrieved scene corresponding to the sampled targeted scene is generated. Generating a retrieved scene corresponding to the sampled targeted scene includes the following. The plurality of modulated antenna patterns and the corresponding plurality of antenna temperatures are fed into a compressive sensing imaging algorithm.

A node including an RU and a control entity is disclosed. The node may receive, from a base station at a control entity of the node, an indication of at least one obstruction for communication via at least one reflective surface. The indication may indicate to the control entity to utilize an RU of the node and the at least one reflective surface for communication. The node may configure, upon receiving the indication of the at least one obstruction, the RU and the at least one reflective surface for communication with the base station. The node may forward communication received from, or forward communication to, the base station via the RU and the at least one reflective surface based on the at least one obstruction for communication.

A reconfigurable antenna includes a bottom plate, a vertically polarized high-density antenna, and a controllable reflector. The controllable reflector is located between the bottom plate and the vertically polarized high-density antenna, and a projection of the controllable reflector on the bottom plate is at a center of a projection of the vertically polarized high-density antenna on the bottom plate. The controllable reflector includes a switch, and the switch is configured to enable the controllable reflector to be in an operating state or an off state.

Disclosed is an electromagnetic-circuit co-design approach for massively reconfigurable, multifunctional, and high-speed programmable metasurfaces with integrated chip tiling. The ability to manipulate the incident electromagnetic fields in a dynamically programmable manner and at high speeds using integrated chip tiling approach is also disclosed. The scalable architecture uses electromagnetic-circuit co-design of metasurfaces where each individual subwavelength meta-element is uniquely addressable and programmable. The disclosed device comprises a large array of such meta-elements. The design relies on integrated high frequency switches designed in conjugation with meta-element for massive reconfigurability of incident amplitude and phase. The disclosed chip is multi-functional and can perform beamforming, high speed spatial light modulation, dynamic holographic projections, and wavefront manipulation.

Various embodiments disclose a method by which a user equipment (UE) performs initial access to a base station by using a large intelligent surface (LIS) in a wireless communication system, and a device therefor. The method comprises the steps of: receiving, through the LIS, a UE search signal transmitted by the base station; transmitting an initial access signal to the base station through the LIS on the basis of resource allocation information included in the UE search signal; transmitting a first LIS control signal for controlling a reflection pattern of the LIS for an uplink signal; and receiving, through the LIS, an initial access response signal transmitted by the base station.