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.

A reflector structure is configured to connect an antenna. The antenna has an excitation source. The reflector structure includes a metal substrate, at least one first flat plate and a second flat plate. The metal substrate is configured to reflect the radiation of the antenna. The at least one first flat plate is disposed on the metal substrate. The second flat plate is floated to the metal substrate along a virtual normal and completely separated from the at least one first flat plate to form a closed slot. A cavity is formed by the metal substrate, the at least one first flat plate and the second flat plate and communicated with the closed slot. The excitation source is projected onto a plane to form an excitation source region. The excitation source region is located in the second flat plate.

A reflector structure is configured to connect an antenna. The antenna has an excitation source. The reflector structure includes a metal substrate, at least one first flat plate and a second flat plate. The metal substrate is configured to reflect the radiation of the antenna. The at least one first flat plate is disposed on the metal substrate. The second flat plate is floated to the metal substrate along a virtual normal and completely separated from the at least one first flat plate to form a closed slot. A cavity is formed by the metal substrate, the at least one first flat plate and the second flat plate and communicated with the closed slot. The excitation source is projected onto a plane to form an excitation source region. The excitation source region is located in the second flat plate.

An antenna device (100) includes an antenna element (102) for emitting and receiving electromagnetic waves, a reflector (104) for reflecting the electromagnetic waves emitted from the antenna element (102), and a substrate (106) on which the antenna element (102) and the reflector (104) are positioned. The substrate (106) defines a main extension plane (108) extending along a horizontal direction (Y) and a lateral direction (X), wherein a vertical direction (Z) extends perpendicular to the horizontal direction (Y) and the lateral direction (X), and thus perpendicular to the main extension plane (108). The reflector (104) has a concave shape (112) in the vertical direction (Z) thereby spatially narrowing in the vertical direction (Z) the electromagnetic waves emitted by the antenna element (102), and has a convex shape (110) in the horizontal direction (Y) thereby spatially widening in the horizontal direction (Y) the electromagnetic waves emitted by the antenna element (102).

An antenna device (100) includes an antenna element (102) for emitting and receiving electromagnetic waves, a reflector (104) for reflecting the electromagnetic waves emitted from the antenna element (102), and a substrate (106) on which the antenna element (102) and the reflector (104) are positioned. The substrate (106) defines a main extension plane (108) extending along a horizontal direction (Y) and a lateral direction (X), wherein a vertical direction (Z) extends perpendicular to the horizontal direction (Y) and the lateral direction (X), and thus perpendicular to the main extension plane (108). The reflector (104) has a concave shape (112) in the vertical direction (Z) thereby spatially narrowing in the vertical direction (Z) the electromagnetic waves emitted by the antenna element (102), and has a convex shape (110) in the horizontal direction (Y) thereby spatially widening in the horizontal direction (Y) the electromagnetic waves emitted by the antenna element (102).

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.

A base station antenna includes a first antenna having first and second spaced-apart columns of first radiating elements therein, which are configured to operate within a first frequency band. An active antenna system (AAS) is provided, which is configured to operate within a second, typically higher, frequency band. The AAS includes a second antenna within a space between the first and second columns of first radiating elements. These first radiating elements may include tilted feed stalks which support higher integration by enabling the first radiating elements to overhang at least a portion of the second antenna.

Provided herein are systems and methods for implementing an over-the-air neural network (OANN) including by receiving, at a relay receiver of a relay node, a signal of interest from a transmitter, directionally re-transmitting the signal of interest from each of a plurality of relay transmitters of the relay node to a corresponding one of a plurality of programmable reconfigurable intelligent surfaces (RIS), reflecting, by each of the plurality of RIS, the corresponding re-transmitted signal of interest, and adjusting, by a neural network controller, a reflection angle of each of the plurality of RIS to direct the reflected signals of interest to combine in a deterministic manner at the relay receiver.

A broadband dual-polarized antenna integrated high-performance balun. The antenna structure consists of three main parts: radiator, feeding structure and reflector. The radiation element consists of four radiation parts with petal shape, forming two pairs of orthogonal dipole antennas. The feeding structure consists of four circuit boards with separated lines, forming resonant structures corresponding to a balance transformer. The reflector enables to direct the beam, increasing the antenna's orientation.