Methods and systems for shaping an electromagnetic wavefront are disclosed. A disclosed method includes tuning a tunable surface in an electromagnetic cavity and receiving the electromagnetic wavefront in the electromagnetic cavity. The electromagnetic wavefront includes a first wave defined by a first wavelength and a second wave defined by a second wavelength. The first wave and the second wave have a shared phase and a shared beam direction in the electromagnetic wavefront. The method further includes reflecting the electromagnetic wavefront within the cavity to repeatedly interact with the tunable surface, and transmitting, after reflecting the electromagnetic wavefront within the cavity, the electromagnetic wavefront from the electromagnetic cavity as a shaped electromagnetic wavefront. The first wave and the second wave have at least one of a difference in phase or a difference in beam direction in the shaped electromagnetic wavefront.

A switchable element, a device and a method for analogue and programmable computing operating on electromagnetic waves having a frequency, wherein the switchable element is configured to configured to, in response to an activation signal, switch from having a first dielectric permittivity for electromagnetic waves having a frequency to having a second dielectric permittivity for electromagnetic waves having the frequency, and the device comprises a plurality of the switchable elements that are adapted to be switched individually in accordance with the computing operation.

A method and apparatus for processing a terahertz frequency electromagnetic beam are disclosed. For example, the method receives the terahertz frequency electromagnetic beam via a metamaterial having a plurality of addressable magnetic elements, where a resonant frequency of each of the plurality of addressable magnetic elements is capable of being programmably changed via an adjustment, and activates selectively a subset of the plurality of addressable magnetic elements to manipulate the terahertz frequency electromagnetic beam.

Systems and methods for designing, optimizing, patterning, forming, and manufacturing symphotic structures are described herein. A symphotic structure may be formed by identifying a continuous refractive index distribution calculated to convert each of a plurality of input reference waves to a corresponding plurality of output object waves. The continuous refractive index distribution can be modeled as a plurality of subwavelength voxels. The system can calculate a symphotic pattern as a three-dimensional array of discrete dipole values to functionally approximate the subwavelength voxels. A symphotic structure may be formed with a volumetric distribution of dipole structures. A dipole value, such as a dipole moment (direction and magnitude) of each dipole is selected for the volumetric distribution to convert a plurality of input reference waves to a target plurality of output object waves.

A resonant wearable antenna system includes a ground plane and an antenna structure positioned over the ground plane. The ground plane includes a first cloth substrate and an array of metamaterial (MTM) unit cells positioned on the substrate. At least one MTM unit cell includes four four-leaf-clover units arranged in a four-leaf-clover pattern and connected to a center unit. Each four-leaf-clover unit includes four leaf units arranged in a four-leaf-clover pattern and connected to a subcenter unit. The antenna structure includes a second cloth substrate and a conductive pattern positioned over the second cloth substrate. The antenna structure is configured to have a first resonant frequency below 1 GHz and a second resonant frequency higher than the first resonant frequency. The array of MTM unit cells is configured to reflect incident waves, from the antenna structure at the first resonant frequency and the second resonant frequency, in-phase.

Reflectarray antenna elements, reflectarrays, and a method of operating an antenna element are described. A reflectarray antenna element includes a patch (14) of electrically conductive material for reflecting an electromagnetic field; a dielectric substrate (12) providing an RF ground; first and second phase control lines (16, 18) of electrically conductive material arranged to interact with electromagnetic radiation with a first polarisation; a first binary switching device (24) having an ON or OFF state disposed between the patch and ground, and configured to selectively electrically couple the patch to ground via the first phase control line; a second binary switching device (26) having an ON or OFF state disposed between the patch and ground, and configured to selectively electrically couple the patch to ground via the second phase control line; a single DC bias input electrically coupled to the patch and configurable to different discrete voltage levels for selectively controlling the states of the switching devices. Selective operation of the first and second binary switching devices occurs by means of the DC bias input provides phase control of electromagnetic radiation dependent on the state of the switching devices. Described is a phase control mechanism of unit cells to enable a reconfigurable/smart reflectarray platform.

A reconfigurable antenna, includes an emissive region, including at least one radiating source designed to emit electromagnetic waves; and an electromagnetic lens, including a set of phase-shifting cells, including switches configured to introduce a phase shift to the electromagnetic waves, and bias lines to bias the switches. The antenna further includes an electromagnetic coupling region, arranged between the emissive region and the electromagnetic lens in order to generate electromagnetic coupling between the electromagnetic waves and the set of phase-shifting cells, wherein the electromagnetic coupling region comprises a set of electrically conductive elements, arranged to form a contour of a resonant cavity guiding the electromagnetic waves towards the electromagnetic lens, the set of electrically conductive elements comprising first tracks electrically connected to the bias lines.

A multiband resonator element which, on the one hand, compensates the components of an electromagnetic field radiated from its phase centre, located on the axis of symmetry of the resonator, to control the polarization purity of a radiating element. On the other hand, it enables the selection of the electromagnetic fields reflected and transmitted on a frequency- and multiband-selective surface. In this sense, this is an innovative element that enables the design of directive radiating elements and with an axial ratio for its circular polarization less than or equal to 1.5 dB for all the angles belonging to the hemisphere centred on broadside. Thus, it can be used in the design of reflectarrays, transmitarrays and any dichroic multiband surface, likewise on metamaterial surfaces.

The disclosed structures and methods are directed to antenna systems configured to transmit and receive a wireless signal in and from different directions. A switchable lens antenna has excitation ports radiating radio-frequency (RF) wave into a parallel-plate waveguide structure, and a frequency selective structure (FSS). The antenna presented herein is configured to operate in two modes depending on an initial steering angle of the RF wave propagating in the parallel-plate waveguide structure. When the initial steering angle is about or less than a threshold steering angle, FSS is OFF due to its stubs being electrically disconnected from the parallel-plate waveguide structure. When the initial steering angle is higher than the threshold, FSS is ON with stubs being electrically connected to the parallel-plate waveguide structure. When ON, FSS provides phase variance to the RF wave propagating in the parallel-plate waveguide structure and increases steering angle of the RF wave.

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.