Abstract: The invention relates to components such as pyroelectric sensors which are particularly sensitive to piezoelectric effects and which, consequently, are disturbed by the mechanical deformations or the vibrations which the component may experience. In order to limit these disturbances, it is proposed to insert, between the chip (10) carrying the pyroelectric layer and the bottom of the package (30), a flexible sheet (42) of silicone which absorbs the deformations of the package without transmitting them to the chip. Ultrasonic bonding of the connecting wires (34) is still possible despite the presence of the flexible sheet. The chip is preferably fixed to a metallized ceramic plate (40) and abutments (44) are preferably provided at the bottom of the package in order to limit the compression of the flexible sheet (42) during the bonding operation.

Abstract: Disclosed is a method enabling the improvement of the multisensor reception of a system of radiocommunications exchanging signals between at least one fixed base station providing for multisensor reception by means of a network of sensors, and the processing of the signals. This method consists, in a transparent manner perceived from the base station, in computing a weighting vector W for the formation of channels at reception. The weighting vector W is estimated by an adaptive algorithm leading to a maximization of the signal-to-noise ratio. Application: mobile radiocommunications. FIG.

Abstract: The device includes a first frequency synthesizer loop with fractional division to a apply a first wide frequency band transposition signal to an input of the first mixing stage of the receiver, a second phase-lock frequency synthesizer loop to apply a second narrow frequency band transposition signal to an input of the second mixer stage of the receiver and a common frequency source coupled to the first loop and to the second loop for the application, to their reference inputs, of a frequency reference signal. Application to wideband (20 MHz to GHz) V/UHF receivers.

Abstract: A magnetic core includes a body made of polycrystalline ceramic and at least one localized gap made of a composite magnetic material. The gap may be preferably fixedly joined to the body by bonding or molding. The magnetic core has applications in inductors or transformers. The inductor preferably has a coil located on the body, which coil is preferably made of multistranded enameled wires.

Abstract: The invention relates to a frequency converter comprising a guide and a non-linear medium (NLM) in which the condition of phase matching between non-linear polarization and created waves is satisfied locally. The object of the invention resides in an additional layer C lying on the medium (NLM), the refractive index of which is such that it increases the conversion yield, for conversion of the incident waves to the waves created within the guide. This layer may be a symmetrization layer whose index is close to the index of the medium (NLM). The conversion yield may be further increased by means of an intermediate layer C.sub.ex, which lies between the layer C and the medium (NLM) and the index of which is close to that of the guide.

Abstract: A device to join up cable sheathings comprises a chamber and a shaft. The shaft houses the cable and is connected in an electromagnetically impervious way to a rear part of the chamber. A front part of the chamber is itself designed to be connected in an electromagnetically impervious way to a casing, for example a connector casing. The conductive surface providing for the impervious electrical continuity between the periphery of the shaft and periphery of the chamber is outside the chamber. This makes it possible to give the internal diameter of the shaft a value that is substantially equal to that of a casing to which the front part of the chamber must be connected.

Abstract: This magnetic head has two magnetic poles separated by a gap. The two ends of the poles are connected by a magnetic layer located beneath these poles. This layer has a zone made of insulator material located beneath the poles. Application to magnetic heads for recording and reading on magnetic media.

Abstract: A method and system to ensure the confidentiality of a local area network when a first terminal of the local area network sends out a first and second plurality of voice messages which, respectively, may and may not be received by a second terminal, consists of providing a signature distributed over the first plurality of voice messages with a portion of the signature substituted for the least significant bit of the first plurality of voice messages. Filtering is provided in the second terminal which extracts the signature from the first plurality of voice messages arriving at the second terminal and which recognizes the signature. The filtering disconnects the second terminal from the network, for a given period of time, if the predetermined message has not been recognized. The method and system to ensure the confidentiality of a local area network is suited for integrated services digital networks (ISDN) applications.

Abstract: A method for digitally demodulating a complex modulation signal and allowing different parameters to be transmitted thereby. The input signal is baseband filtered and a complex demodulation is performed on the first subcarrier at a frequency Fp to obtain a correction signal, after squaring. The input signal is demodulated around a frequency exactly equal to twice the frequency of the first demodulation in order to obtain output signals which exhibit a frequency error with respect to 2Fp. This frequency error is corrected by multiplication with the previously derived frequency correction signal. The corrected signal is filtered at a frequency lower than 1 Hz, in order to obtain a signal giving the phase error at a frequency 0, that is to say that of the subcarrier at 2Fp. The signal makes it possible to correct the phase of signals which were previously frequency corrected in order to obtain two signals which are complementary to one another and transmitted by quadrature modulation around the frequency 2Fp.

Abstract: A frequency converter can be used, in particular, to generate optical waves in the medium infrared (3.12 .mu.m) range from optical sources in the near infrared range. It comprises a heterostructure semiconductor waveguide formed by an alternation of layers of material M.sub.I and M.sub.II, at least one of these materials being a non-linear semiconductor and the plane of the layers being parallel to the direction of propagation of the electromagnetic waves in the waveguide.

Abstract: The disclosure concerns a dual-mode ISDN/STN visiophone terminal, including at least one audio equipment and one video equipment respectively connected to an ISDN via a dual-mode ISDN/STN audio coder/decoder incorporating an ISDN audio coder, an ISDN audio decoder, an STN audio coder and an STN audio decoder, and via a dual-mode ISDN/STN video coder/decoder incorporating an ISDN video coder, an ISDN video decoder, an STN video coder, and an STN video decoder, wherein in order to provide an answering/recording function in said visiophone terminal a RAM memory is used to store audiovisual messages in STN mode, and wherein the outputs of the ISDN audio and video decoders are connected respectively to the inputs of the STN audio and video coders in order to record in the RAM an audiovisual message sent by a calling party via a remote terminal, and wherein the outputs of the STN audio and video decoders are connected respectively to the inputs of the ISDN audio and video coders in order to send an audiovisual mess

Abstract: The device includes a set of processing macromodules connected in cascade and organized in accordance with hierarchical levels. Each macromodule is structured so as to partition the current image into macroblocks of a determined size corresponding to its hierarchical level so as to transmit a motion vector field to the block which follows it, and includes first circuits for calculating the displaced inter-image differences DFDi and the gradients on the basis of the values of luminance of the pixels of the video image and of the displacement vectors of each image preceding or following the current image; second circuits for performing blockwise the summations of the displaced inter-image differences and third circuits for performing corrections of the displacement vectors of the image.

Abstract: A winch operates with a hydraulic motor which is supplied by a servo-valve. The servo-valve is connected as a 3-way system so that the supply hose used as a discharge when the load is being winched up is connected directly to the fluid return and so that during the descent, this motor is no longer supplied with high pressure and the fluid is circulated in a closed circuit without pressure. Fluid is refreshed with a flow rate low enough so that it does not excessively increase the supply of energy, but high enough that it limits the overheating of the fluid.

Abstract: A back projection device comprises an image generator (GI), an onward reflection mirror (MR) and at least one optical component (OM) capable of reflecting certain types of light beams almost entirely and reflecting certain other types of light beams almost entirely, said component being located in the proximity of a screen (E). The selection of optical behavior of the component (OM) may be done as a function of the polarization of the light beam, or else also as a function of its orientation with respect to said component (OM). Application: displays.

Abstract: The method of identifying, in a memory space of the node, a virtual circuit of a network to which the cell belongs, on the basis of virtual path numbers VPI and virtual channel numbers VCI contained in the header of the cell. This method includesaddressing the memory space of the node on the basis of the virtual path number VPI contained in the header of the cell to identify a first context zone in this space indicating the range of virtual channels that can be used by the cell for this VPI,and addressing a second context zone on the basis of a virtual channel number VCI contained in the header of the cell and a basic address read in the first context zone to obtain the list of directions to be taken by the cell at the exit from the node, as well as the new header.

Abstract: The present invention pertains to the analysis of the frequency spectrum of a signal by a high-resolution method that is more precise than the Fourier transform when all that is available is a small number of samples of the signal. It pertains more particularly to a method for the autoregressive modelling frequency spectral analysis of a signal, known as Burg's maximum entropy method, and consists of a regularization of this method by means of a criterion similar to that already known to have been used in order to regularize the method of autoregressive spectral analysis known as the least error squares method, while at the same time keeping the advantages of Burg's maximum entropy method which are that it can be used in real time with a lattice type computation structure, that it can be extended to multisegment configurations and that it is robust with respect to computation noise, errors of quantization and rounding-off operations.

Abstract: Device for continuous phase modulation, produced from a frequency synthesizer including a variable oscillator and a phase-locked loop with, in series, a frequency division circuit, a phase comparator and a low-pass filter. In order to reduce modulation in the loop, the modulation is applied not only to the input of the synthesizer but also, in compensation, in the loop. In order to eliminate the modulation residue in the loop, a control signal for the oscillator is derived by a circuit which performs a correlation between the residue of the modulation and the output signal from a filter producing the same filtering effect as the loop, and which receives the modulation signal from the input of the synthesizer.

Abstract: The disclosure relates to the deployment and maintenance of a belt of autonomous sensors fitted out with warning sensors to monitor the area surrounding one or more sensitive points. It relates especially to anti-missile and anti-aircraft warning systems for naval surface ships against missiles and aircraft flying at low and very low altitudes. It consists in controlling the paths of the drones solely by means of their radius of curvature for which they receive an instructed value from the reference point or points. This instructed value is encoded by a frequency of a radioelectric signal sensitive to the Doppler effect. A modification of this instructed value of radius of curvature as a function of the signal of a proximity sensor makes it possible to avoid all problems of collision and to keep the drones at equal distance from one another. This mode of control proves to be particularly efficient and, at the same time, very simple.

Abstract: Semiconductor hybrid components, especially linear infrared detectors produced by hybridization. A main substrate has integrated thereon active elements which cannot be produced on a silicon substrate. The substrate is made, for example, of AsGa, InP, HgCdTe or PbTe. Several silicon chips are mounted on the main substrate, by hybridization using indium balls. These chips include the read and multiplexing circuits. The silicon chips remain of limited size (a few millimeters) so that the differential thermal expansion stresses are limited, but the detection array may be produced as one piece without butt-joining. It is therefore possible to produce arrays of great length (several centimeters) and of high resolution (at least a thousand points).

Abstract: A process for estimating disparity between images of a stereoscopic image by carrying out a hierarchical decomposition of each monoscopic image (Ir(t), Il(t)), by levels of resolution in order to build at least three pyramids of images of increasing resolution including one low-frequency image pyramid and two high-frequency image pyramids in the horizontal and vertical directions of the images. Subsequently a disparity D is estimated at the coarsest level of resolution and the estimate is refined in each level as the resolution increases.