Provided herein are reconfigurable intelligent surfaces (RIS) including a surface, a source tile positioned on or proximate a first side of the surface and including a source power layer including a power amplifier and a transmitter coil configured to generate an electromagnetic field and a radio frequency (RF) layer configured to receive power from the source electromagnetic field, and a patch antenna grid for reflecting a RF signal, and a plurality of extender tiles positioned on or proximate the first side of the surface, the extender tiles each including an extender power layer including a passive transceiver coil for receiving the source electromagnetic field and relaying the source electromagnetic field as an extender electromagnetic field and an extender RF layer configured to receive power from the extender electromagnetic field, and an extender patch antenna grid for reflecting at least one of the RF signal or a second RF signal.

A photoconductor assembly includes a substrate formed of an undoped and single-crystal semiconductor material that is configured to absorb electromagnetic energy, a plurality of electrodes arranged normal to the substrate, and a power supply that applies a voltage to the electrodes for modulating the electromagnetic energy through the substrate.

Examples disclosed herein relate to a metastructure reflector in a wireless communication system. The metastructure reflector has a transceiver unit adapted to receive transmissions from a base station, a radiating structure having a plurality of subarrays of radiating cells to radiate the transmissions to at least one user equipment, the at least one user equipment in a non-line-of-sight area of the base station, and a subarray controller to control a plurality of subarrays of the radiating structure to radiate the transmissions in multiple directions.

Described embodiments include a system, method, and apparatus. The system includes an antenna comprising a sub-Nyquist holographic aperture configured to define selectable arbitrary complex radiofrequency electromagnetic fields on a surface of the antenna. A mapping engine models an environment within a space radiateable by the antenna. The environment includes a target device and a human being. An optimization circuit selects responsive to the model of the environment a power transmission regime. The power transmission regime includes radiation pattern shaped to wirelessly transfer electromagnetic power from the antenna to the target device without exceeding a radiation exposure limit for humans. A gain definition circuit selects a complex radiofrequency electromagnetic field implementing the selected power transmission regime from the at least two selectable arbitrary complex radiofrequency electromagnetic fields. An antenna controller defines the selected arbitrary complex radiofrequency electromagnetic field in the sub-Nyquist holographic aperture.

A flexible microwave antenna having a “fish-scale” ground plane is provided. The approach represents a significant advance in the combined thickness and flexibility that can be achieved, especially when using relatively thick substrates which are important for optimum antenna performance. An increase in gain was observed when bent in a positive radius of curvature and further reduction of back radiation.

An antenna for wireless communication includes a spherical reflector and one or more feeds. The spherical reflector includes an inner portion made of material that reflects radiofrequency (RF) beams, and an outer portion positioned on an edge of the inner portion, the outer portion being made of metamaterials that can be controlled to be reflective of or transparent to RF beams. The one or more feeds are configured to form one or more RF beams reflected off the spherical reflector. In some implementations, the antenna includes one or more processors configured to form one or more RF beams using the one or more feeds, and control at least a part of the outer portion of the spherical reflector to reflect an RF beam of the one or more RF beams or be transparent to the RF beam based on the one or more RF beam.

An object is to advantageously control a phase of an electromagnetic wave with high efficiency at target operational frequency band. A phase control device (10) comprising a two-dimensional array of three-dimensional units (101) and configured to shift a phase of an electromagnetic wave passing through the three-dimensional units (101). The two nearest three-dimensional units (101) having same phase shift coverage are configured such that the distance difference from phase center of the phase control device (10) to the units (101) is a wavelength of a reference frequency f.sub.k, and the reference frequency f.sub.k is higher than center frequency f.sub.c of operational frequency band and not higher than the highest frequency f.sub.h of the operational frequency band.

A coherent frequency modulated receiver for receiving and detecting arriving optical signals which comprises an electrically controllable optical beam scanner receiving optical input beams arriving at different angles in a field of view of the electrically controllable optical beam scanner, the electrically controllable optical beam scanner conveying a scanned optical input beam as its output optical beam; a grating coupler responsive to the output or reflected optical beam of the electrically controllable optical beams scanner, the grating coupler having a waveguided output; an optical local oscillator laser having a waveguided output; an FMCW signal generator; an optical modulator responsive to the optical waveguided outputs of the optical local oscillator laser and also to an electrical FMCW signal from the FMCW signal generator; a pair of second order non-linear optical elements for frequency upconverting respective outputs of the optical modulator and the grating coupler; and at least one photodiode optically coupled to an outputs of the pair of second order non-linear optical elements.

To accurately estimate frequency characteristics from structural parameters of a frequency selective surface. A frequency selective surface design apparatus includes an LC generation unit 20 that receives an input of a structural parameter, and generates an inductance L and a capacitance C of a unit cell, a corrected resonance point calculation unit 30 that receives the number n of times of calculation input from an outside, the inductance L, and the capacitance C, models a correction circuit by using a circuit in which a virtual capacitance is connected in parallel via a transmission line to each distribution inductance obtained by division of the inductance L by the calculation number n and the transmission line is terminated at the capacitance C, and calculates a corrected resonant frequency fC from the impedance of the correction circuit, and a characteristic calculation unit 40 that receives inputs of the inductance L, the capacitance C, and the corrected resonant frequency fC, calculates a pre-correction resonant frequency from the inductance L and the capacitance C, obtains a correction coefficient by dividing the corrected resonant frequency fC by the pre-correction resonant frequency, and calculates a corrected return loss and a corrected insertion loss.

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.