Thomson-csf

Centre National De La Recherche Scientifique

Sorbonne Université

Ecole Superieure De Physique Et De Chimie Industrielles De La Ville De Paris

Paris Sciences Et Lettres

Ultimetas

Thales

Université Pierre Et Marie Curie (paris 6)

Université Des Sciences Et Technologies De Lille

Jean Chazelas

Jean-Pierre Huignard

Brigitte Loiseaux

Philippe Bonniau

Marc Turpin

Daniel Dolfi

Bernard Estang

Philippe Souchay

Charlotte Tripon-Canseliet

Bernard Perrier

Jerome Lecuellet

Luigi d'Auria

Guy Le Parquier

Yves Canal

Alain Becker

Jean-Charles Renaud

Olivier Prevotat

Paul Sergent

Jean-Fran&ccedil;ois Silvain

Didier Decoster

Francedillaois Renault

Maxime Lailler

Sandrine Trombert

Charlotte Canseliet

El Hadj Dogheche

Jean-Paul Martinaud

Malek Zegaoui

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.

Metasurface device

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.

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.

Accurate synchronizing device

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.

Method for the making soldering flux and resulting weld joint

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. An optoelectronic system is used to overcome the variations in the characteristics of the semiconductor component, thus averting especially a temperature stabilization of this component.

Optoelectronic system for the testing of an antenna

Reconfigurable multipoint temperature sensor

Reconfigurable birefringent fiber-optic sensor with shape-memory alloy

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. The conversion system according to the invention comprises a first N-bit analogue-to-digital converter doing a very precise but ambiguous conversion of the electric signal, and a second analogue-to-digital converter to eliminate the ambiguity.

Analogue-to-digital converter and analogue-to-digital conversion system

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.

Device for the airtight closing of a package with fast open-and-shut

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.

Structure with intrinsic damage control, manufacturing processes and

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.

Device for the optical processing of electrical signals

Process and system for determining the position and orientation of a

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.

Optical fiber stress detector using amplitude modulation

A structure which includes a composite material formed of a plurality sheets forming plies. A casing is formed between two of the plurality of sheets forming the composite material, the casing having an internal diameter. Further, an optical fiber is located within the casing and has an external diameter which is less than the internal diameter of the casing, the optical fiber also having a slow axis and a fast axis of propagation.

Optical connection device and data processing apparatus fitted with

Growing community of inventors

Paris, France

Jean Chazelas