Abstract: A metasurface device includes a ground structure able to have a ground plane function, the ground structure being able to be alternately in an insulating state, wherein it prevents the propagation of the surface wave over the front surface of a substrate so as to prevent the antenna element from radiating, and in a conductive state, wherein the ground structure has the ground plane function, allowing the propagation of the surface wave over the front surface of the substrate from the emission/reception device to the conductive patches, or vice versa, the ground structure being able to change from the insulating state to the conductive state through illumination of the ground structure at a wavelength called a switching wavelength.

Abstract: A metasurface device includes an antenna element formed on the front surface of a substrate, the antenna element comprising a two-dimensional array of electrically conductive patches spaced from one another and having dimensions smaller than the operating wavelength of an emission and/or reception device, the antenna element being able to radiate in a direction having a component perpendicular to the front surface of the substrate when the ground structure has a ground plane function, the substrate comprising a layer, called a connection layer, made of photoconductive semiconductor material, in direct physical contact with the conductive patches, the semiconductor material being insulating when it is not illuminated and able to be conductive when it is illuminated at a reconfiguration wavelength.

Abstract: A radiating element of an antenna includes at least one wire-like nanostructure, each wire-like nanostructure extending in the same direction, called common direction, between a first end and a second end, and an inductor connected to each first end of a nanostructure, the inductor being formed from a first conductive material, the inductor extending in a plane normal to the common direction, the first conductive material having an electrical conductivity that varies under the effect of a variation of an electric field applied within the first conductive material.

Abstract: A switch includes a substrate and a microwave line comprising two tracks produced on the substrate, an active zone of the substrate being bounded by the two conductive tracks and connecting the two tracks. The switch comprises a set of at least one DC line, intended to convey a DC current, the DC line comprising two electrodes that are distant from each other and that are connected by a separation zone of the substrate, the separation zone being able to be made conductive when it is illuminated by the optical control beam so as to establish an electrical contact between the two electrodes, the two electrodes being separated by a separation plane of the DC line, the separation plane passing through the centre O and being perpendicular to the plane of the active zone.

Abstract: A switch includes a substrate and a microwave line comprising two tracks produced on the substrate, an active zone of the substrate being bounded by the two conductive tracks and connecting the two tracks. The switch comprises a set of at least one DC line, intended to convey a DC current, the DC line comprising two electrodes that are distant from each other and that are connected by a separation zone of the substrate, the separation zone being able to be made conductive when it is illuminated by the optical control beam so as to establish an electrical contact between the two electrodes, the two electrodes being separated by a separation plane of the DC line, the separation plane passing through the centre O and being perpendicular to the plane of the active zone.

Abstract: A device for switching an electrical signal, controlled by an optical wave and having an on state and an off state, which can be inserted into a microwave transmission line, comprises a semiconductor substrate on which two conductive tracks are formed, these tracks being separated by a gap providing electrical insulation between the two tracks and each being connected to an input port and an output port, in the on state the electrical contact between the two tracks being established by illuminating the substrate in the region of the gap by means of the optical wave, the input impedance and the output impedance of said switching device being mismatched to the impedance of the transmission line in the off state and are matched to the impedance of the transmission line in the on state.

Abstract: A device for electro-optical sampling of a microwave frequency signal is disclosed. In one aspect, the device includes a microwave transmission line for transmitting a microwave signal, the microwave line including an interruption zone configured to be rendered conducting under the effect of an optical control signal so as to carry out a function of optically controlled interrupter switch. The device also includes, in the interruption zone, a layer of nanostructured semiconductor material, including a periodic or quasi-periodic tiling of nanostructures. The layer of nanostructured semiconductor material is placed, at the level of the interruption zone, in suspension or on a dielectric material of lower refractive index than the refractive index of the semiconductor material, the layer of nanostructured semiconductor material being able to carry out the function of optically controlled interrupter switch.

Abstract: A device for switching an electrical signal, controlled by an optical wave and having an on state and an off state, which can be inserted into a microwave transmission line, comprises a semiconductor substrate on which two conductive tracks are formed, these tracks being separated by a gap providing electrical insulation between the two tracks and each being connected to an input port and an output port, in the on state the electrical contact between the two tracks being established by illuminating the substrate in the region of the gap by means of the optical wave, the input impedance and the output impedance of said switching device being mismatched to the impedance of the transmission line in the off state and are matched to the impedance of the transmission line in the on state.

Abstract: A device for electro-optical sampling of a microwave frequency signal is disclosed. In one aspect, the device includes a microwave transmission line for transmitting a microwave signal, the microwave line including an interruption zone configured to be rendered conducting under the effect of an optical control signal so as to carry out a function of optically controlled interrupter switch. The device also includes, in the interruption zone, a layer of nanostructured semiconductor material, including a periodic or quasi-periodic tiling of nanostructurees. The layer of nanostructured semiconductor material is placed, at the level of the interruption zone, in suspension or on a dielectric material of lower refractive index than the refractive index of the semiconductor material, the layer of nanostructured semiconductor material being able to carry out the function of optically controlled interrupter switch.

Abstract: A synchronization device which synchronizes signals transmitted from a transmitter to receivers. The transmitter includes a generator for generating a synchronization signal having a recurrence period substantially equal to the minimum resolution of the journey time between the transmitter and the receiver. Each receiver includes a controllable delay for delaying the synchronization signal and a synchronization loop downstream of the delay. The synchronization loop includes a semi-reflecting plate, a correlator and a device for slaving the delay depending on the correlation. A signal received by the receiver is synchronized when the correlation function of the two successive recurrences of the synchronization signal passing through the semi-reflecting plate is at a maximum. The device may be used for accurate synchronization of information distributed from a transmitter to mutually remote receivers, for example for operating complex electromagnetic or optical rigs.

Abstract: To improve the resistance of a solder to strains, especial thermal strains, superelastic particles are incorporated into the solder in a proportion by volume of 10 to 30% approximately. So that this incorporation can be done, the particles are coated with a metal, for example copper, that is wettable by the solder.

Abstract: This optoelectronic system for the testing of a main antenna comprises: a test antenna designed to be placed in the field of transmission or reception of the main antenna; an optoelectronic component associated with the test antenna alternatively receiving and sending optical signals from/to remote transmitters/receivers and receiving and/or sending optical signals from/to the test antenna; an electric matching circuit connected between the optoelectronic component and the test antenna. This system thus enables the testing on the spot of an antenna (for example a radar antenna) without disturbing the radiation pattern of this antenna. This semiconductor component is therefore alternatively a modulator or a detector of light radiation, and it is connected by optical fibers to emitters and adapted detectors located out of the field of the antennas to be tested. The cables formed by dielectric materials do not disturb the radiation pattern of the antennas.

Abstract: A temperature sensor having a light fiber connecting a light source and a reflectometer. Temperature measurement zones are formed by sensing elements made of shape-memory alloy. The elements exert a stress on the fiber when they are subjected to an increase in temperature due to their memorized state. The change in temperature is detected by the reflectometer.

Abstract: A fiber-optic sensor composed of elements made of shape-memory alloy which, in one of their memorized shapes, impose a stress on the optical fiber, which stress is easy to locate with an interferometer. The multisensor configuration is thus easily reconfigurable.

Abstract: An N-bit analogue-to-digital converter can increase the resolution by 3 bits, by very precise coding of the differential phase at the output of the electro-optic phase modulator controlled by the electric signal to be converted. The optical signals obtained are processed by an electro-optic device that outputs electric signals that are functions of the sine and cosine of the phase. A coding device uses the symmetry of the trigonometric circle partitioned into four consecutive sectors between 0 and 27.pi. in order to convert the absolute values of the electric signals obtained on (N-3) bits, independently of the home sector of the phase. A transcoding device uses the value of the sine and cosine coded on (N-3) bits, to output a value V of the electric signal, on N bits, as a function of the home sector.

Abstract: A closing device, for airtight closing of a package by use of a removable lid, has a facing lid fixedly joined to the package and springs made of shape memory alloy resting on the lid and the facing lid. The facing lid may be fixedly joined to the package by brackets or by other fixing mechanisms. These fixing mechanisms may include screws or may include a groove and tongue arrangement. The fixing mechanism may also include a ring made of a shape memory alloy forcing a flexible part of the facing plate against the package.

Abstract: Disclosed is a structure at least partially comprising a composite material, the material being made by means of sheets of fibers embedded in a matrix, the different sheets forming plies of the material, the material comprising intrinsic means for the detection and localization of a mechanical irregularity, these means comprising at least one polarization-maintaining birefrigent optical fiber having a so-called slow axis and a so-called fast axis, embedded in the matrix and describing a known path inside the material, wherein the optical fiber is included inside a casing with an internal diameter that is greater than the external diameter of the fiber.

Abstract: A device for the optical processing of electrical signals. An optical source (L) emits a multiple-wavelength optical beam (B1). A modulator (MOD) modulates this beam. An optical fiber (F) receives the modulated beam and delays the components corresponding to the different wavelengths differently. A dispersive grating disperses wavelengths contained in the modulated beam in different directions. A spatial light modulator controls the level of optical intensity of different directions of the dispersed beam. An optical detection system receives the beam processed by the spatial light modulator. Such a device may find particular application to a transverse filter and microwave signal correlator.

Abstract: The present invention relates to a process and a system for determining the position and orientation of a mobile, and to applications thereof.In order to ascertain both the position and orientation of a mobile, the invention proposes an interrogation/response process whose particular feature is to supply, to a given interrogation, two responses which are distinguished on the one hand, by different modulating frequencies and, on the other hand, by the fact that they are transmitted according to two patterns which differ in aim relative to one another. It is then possible, simply by measuring the angular deviation of either one of the two responses, and simply by measuring the ratio of the amplitudes of the two responses received, to deduce on the one hand the angular position .phi. and on the other hand the orientation .theta. of the mobile.The applications in the automobile sector are numerous (anticollision, control of road traffic and of compliance with the highway code, automatic toll points, etc.).

Abstract: An optical fiber stress detector in which the light beam transmitted in the optical fiber which has to detect stresses is modulated in amplitude by a microwave alternating signal. The signal coming from the fiber is demodulated and then transmitted to a detector which measures the phase-shift existing between the demodulated signal and a signal derived from the modulation alternating signal. Application to the detection of stresses in any composite structures such as public constructive works, aircraft wings etc.