Abstract: The disclosed method uses the ancillary antennas of a radar, and consists in determining the positions of the phase centers of these ancillary antennas, compensating for the difference in optical path between the reflection lobe of the processed channel and that of the ancillary channel, and generating a synthetic channel by an SLO type processing in performing a coherent subtraction between the processed channel and the ancillary channels used, on the desensitized zone of the doppler distance/frequency ambiguous domain of each of the processed channels.

Abstract: A method for positioning plural electromagnetic sensors in an array including the steps of: (1) designating one of the two sensors of the plural sensors that are a greatest distance apart as a point of origin of a reference system, (2) encoding in genotype form, the coordinates of the sensors relative to the reference system, and (3) applying a genetic algorithm to the encoded genotypes to obtain a given phenotype associated with a desired pattern. The method can be applied to the optimization of antenna arrays, especially planar or linear arrays.

Abstract: An acoustic probe and a method for making the same. The probe includes a novel interconnection network consisting of two portions, i.e., a first portion in which M.times.N conductive paths have a section contacting M.times.N piezoelectric transducers and are arranged at a pitch (P.sub.N) in a direction (D.sub.x) and at a pitch (P.sub.M) in direction (D.sub.y) within the acoustic absorption material; and a second portion in which the M.times.N conductive paths are arranged on M dielectric substrates spaced apart at a pitch (P'.sub.M) and each provided with N paths are arranged at a pitch (P'.sub.N). A method for making the acoustic probe is also disclosed. The dielectric substrates may advantageously be flexible printed circuits optionally including chips.

Abstract: A surface acoustic wave filter having three acoustic pathways. The first acoustic pathway is made up of a first transducer including a first and second bonding pad and is arranged between two reflectors to form a first resonator. The second acoustic pathway is made of a second transducer including a third and fourth bonding pad and is arranged between two reflectors to form a second resonator. A third acoustic pathway is made of a third transducer including a fifth and sixth bonding pad and is arranged between two reflectors to produce a third resonator. Each bonding pad of the transducers is linked to a specified potential.

Abstract: A device to control the aiming and focusing of laser systems on a target comprises at least one reflecting false target (21) positioned and oriented substantially identically to the target (3), a lens (12) for the focusing of the beam on this false target, a separator device (11), a wavefront analyzer (35), a mirror (33) and a semi-reflective plate (32), the beam (1) getting focused, at the end of the system, on the false target (21) after getting reflected on the separator device (11). A part (31) of the beam with the same wavelength as that of the part reflected by the separator device (11) goes through this device and the semi-reflective plate (32) to get directed towards the wavefront analyzer (35). The beam reflected by the false target (21) goes through the separator grating (11) to get reflected on the mirror (33) and the semi-reflective plate (32) to get directed towards the wavefront analyzer (35).

Abstract: Method for fabricating thermally cooled electronic cards. A card of any kind is covered with a rigid heat sink shaped to fit the card and is attached thereto. The heat sink is formed in such a way that it fits as closely as possible the shape of the printed circuit. The printed circuit has components on one or both faces so that it is possible to increase the surface thermal coupling between the sink and the board. An optical sensor using a laser beam may be used.

Abstract: A method for the control of a display screen whose pixels are cells producing light is used to minimize certain image defects known as excess brightness defects caused by major variations in the number of cells activated. For this purpose, the invention operates on the sub-division of the activation times of the cells during a given cycle time to reduce a time during which cells, selected as a function of their luminance level, are the only ones to be activated. The disclosed method can be applied especially to the control of alternating type plasma panels.

Abstract: A broadband array antenna which delivers an axisymmetric main lobe. The antenna includes patches arranged with an interruption of periodicity in one of the planes and is corner-fed by tree like feed lines from a central point of energization. Opposite each path is a parasitic element for broadening the band. This device can be used in particular with measurement radar.

Abstract: A semiconductor component of the heterojunction bipolar transistor type comprises, on a substrate, a collector, a base and a mesa-shaped emitter resting on the base. The bipolar transistor furthermore comprises electrically insulating elements in contact with the base and the flanks of the emitter mesa, said elements having a width of the same magnitude as the width of the mesa and providing the component with greater stability. Furthermore, a method for the manufacture of a component of this kind comprises in particular a step for the ion implantation of insulating ions through the constituent layer of the emitter mesa so as to define the electrically insulating elements.

Abstract: A process for spacing ATM cells traveling through an ATM switch and emitted by ATM sources multiplexing diverse profiles destined for one or more networks of specified bit rate. First, the sources emitting cells destined for the same network are aggregated and given a standardized global CBR or VBR profile, the sources being assigned a specified priority. Next, the priorities of each of the sources are taken into account so as to allow specified qualities of service, and the sources are combined by multiplexing CBR and VBR profiles so as to obtain a source having a globally VBR or CBR profile, whilst also preserving the characteristics of the sources with CBR profile in the case of a globally VBR profile. Sharing the passband of the physical link supporting the streams of outgoing cells, between the VBR and CBR profiles, then takes place, and the remainder of the passband which is not used up by the above VBR and CBR profiles is allotted to so-called complementary sources of UBR profile.

Abstract: Disclosed are a method and a device for the removal of ambiguity in distance. The method computes the distance of the targets detected by the radar using several estimation functions (21, 22, 23). When the estimation functions give substantially the same result, the targets are defined as being in the field of non-ambiguous distances and when the estimation functions give different results, the targets are defined as being in the domain of ambiguous distances. Application especially to frequency-shift keying, continuous-wave radar for automobile traffic control.

Abstract: Method of signal processing application graphical entry with the aid of a digital computer.

Abstract: A process for the vector quantization of low bit rate vocoders, including determining a coding region by surrounding with an envelope a scatter of points of an autocorrelation matrix of reflection coefficients of a filter configured to model a vocal tract, wherein the envelope has a shape selected from the group consisting of a hyperellipsoid shape and a pyramidal shape, the envelope being centered at the barycenter of the scatter of points; determining principal axes of the volume of points inside the envelope; projecting area coefficients of the autocorrelation matrix onto the principal axes; partitioning the interior volume of the envelope into elementary volumes; and coding partition coefficients resulting from partitioning the interior volume on the basis of coordinates of said partition coefficients in a space defined by the principal axes of the volume of the points inside the envelope, while allocating as code values only values corresponding to locations of the elementary volumes in which said partit

Abstract: An illumination device comprises a light source coupled to a waveguide. the waveguide comprises a diffracting element capable of diffracting emergent light rays coming from the source, in a direction substantially perpendicular to the surface of the waveguide. A device of this kind is particularly well-suited to transmissive display screens of the liquid crystal display screen type. It can generate a highly collimated, polarized light.

Abstract: The transducer according to the invention, driven in differential mode, consists of at least a first transducer (5) and a second transducer (6) which are connected in parallel so as to obtain the symmetry of the differential inputs, respectively forming a first and a second acoustic channel; the two transducers (5, 6) exhibiting a specified longitudinal offset with respect to one another. Applications: mobile radio filters.

Abstract: This electrical control device with crosstalk correction includes several devices each electrically controllable by a limiter resistor. The current limiter resistors are resistive limiter elements in plane layers positioned on a first substrate face. At least one resistive coupling element is positioned transversally to each resistive element and interconnects these resistive elements.Applications include electrical control of electromagnetic or electrooptical devices, notably the control of magnetic write/read heads.

Abstract: The invention relates to the processing of the multiple paths in an interrogator station which, in response to a salvo of interrogations, receives responses in the form of pulses. The station comprises at least two reception channels. The responses to each interrogation of one and the same salvo are classified by order of appearance. A value of dispersion of the energies is estimated, for each channel and each salvo, on the responses having the same classification. Since the first classified response is, by assumption, considered to have arrived by a direct path, the following responses will be eliminated, on the grounds that they have been received after passing through multiple paths, if their values of dispersion of energy on the two paths are not equivalent to those of the first response.

Abstract: Optical emitting head including a laser and an external optical modulator. The modulating signal is modulated by an electrical signal proportional to 1-e, e being the noise power superimposed onto the laser signal, before being applied to the optical modulator. The invention is suitable for fibre optical transmission applications.

Abstract: The read circuit can be applied to optomechanical scanning imaging devices. The circuit is designed for the reading of batteries of photodetectors comprising a specified number N of detection channels, each constituted by N.sub.d sensors positioned in the scanning direction, such that each point of an image is successively analyzed by N.sub.d sensors of a channel. The circuit includes a current summation scale, associated with each detection channel, formed by a specified number M of current summation circuits and coupled to the detection channel by means of a voltage-current conversion device. Application to the thermal imaging devices.

Abstract: A spectral analysis carried out on the beat signals obtained by the mixing of a transmission signal, the frequency of which is modulated in the form of recurrent sawteeth, with this same signal after it has been transmitted, reflected and then received. The spectral analysis is based on the computation of self-correlation coefficients enabling the definition of the spectral components. For this purpose, the coefficients are computed at each sawtooth and are combined with the coefficients determined with the most recent previous sawteeth to give so-called global coefficients, from which the spectral components sought are restituted in a conventional way. Application especially to altimeters for the measurement of small heights.