Abstract: A system of emission array with several pairs of emitting transducers to emit simultaneously and covering contiguous frequency sub-bands of a band B. The sub-bands have a width which is less than or at most equal to the width inducing an acceptable displacement of the directivity lobes of the emission pattern of a pair of arrays. The emitters of a single pair are spaced by a distance of L.sub.i and emit signal pulses at frequency f.sub.i and of duration .tau..sub.e 1/.DELTA.f, the products L.sub.i f.sub.i being equal for all the pairs of emitters.The emission patterns of the various pairs of emitters accordingly coincide precisely, and, as the emitters are supplied with signals emerging from the oscillators which are in phase at the center of the pulse of duration .tau..sub.e, the pulse resulting from the superposition of the emitted signals is compressed in time.

Abstract: In a radiology installation equipped with a picture-tube video camera for producing images in rapid succession, the electron beam of the camera tube has a first intensity at the time of readout of one image on the sensitive tube surface and a second non-zero intensity of substantially lower value than the first between readout of one image and write-in of the next. A control circuit for modifying the grid voltage of the camera tube is accordingly provided for varying the intensity of the electron beam.

Abstract: A high frequency digital synthesizer is provided with aperiodic correction optimizing the spectral plurity, including:a generator of reference clock signals of frequency F.sub.C,a computing device, which, from a frequency increment of the signal to be synthesized, delivers, on the one hand, uncorrected pulses of frequency F.sub.Sj shifted in the time with respect to the signal of frequency F.sub.S to be synthesized by an amount .DELTA.t at most equal to 1/F and, on the other hand, a time error signal corresponding to the shift .DELTA.t and a correction circuit which is initiated by each of the frequency pulses F.sub.Sj for delaying the signal F.sub.Sj by a maximum time when the time error signal is zero by an amount equal to the maximum time reduced by the shift .DELTA.t indicated by the time error signal.

Abstract: The optical and electronic equipment normally carried by an aircraft pilot's helmet is carried by a support element which is placed at a distance from the helmet and accordingly relieves the load on the pilot's head. The support element is maintained in a predetermined position location with respect to the helmet by means of a detection assembly, a computer for determining errors in positioning, a control circuit which generates signals corresponding to these errors, and a set of jacks controlled by the error signals for modifying the position of the support element with respect to the aircraft structure and cancelling the positioning errors.

Abstract: The mobile unit makes it possible to fire a plurality of shots rapidly, and to leave the firing location immediately afterwards. The unit includes a carrier vehicle (1), a mortar (2) mounted via an articulation unit (4) on a base plate (6). Means are provided for rapidly setting the base plate on the ground so as to rest thereon during shooting. The aforesaid means may pull up the aforesaid plate so that the vehicle may move away rapidly from the shooting location. The primary object of these means is to provide the carrier vehicle with a retractable suspension which makes it possible to lower the vehicle to the ground. An elastic connection (8) is provided between the base plate (6) and the frame (7) of the carrier vehicle to provide for relative movement between the assembly made up of the mortar and the base plate on the one hand, and the frame, on the other hand. The aforesaid invention is of interest to military vehicle manufacturers.

Abstract: A microwave reflector having metallic surfaces and nonmetallic surfaces is perfectly reflecting for the waves of a first polarization and partly transparent for the waves of a second polarization orthogonal to the first. The reflector is primarily applicable to radar systems.

Abstract: This phase and frequency detector, receiving two logic input signals R and V, comprises a set of 2k+2 memory cells, cascade arranged and linked in twos by 2K+1 control cells, capable especially of transferring the information contained in the changes of state of the signals R and V, from the end memory cells to which they are respectively applied, and by each of the directions respectively, to a memory cell MU.sub.n or MD.sub.n (depending on whether the signal R is ahead or delayed with respect to the signal V), this cell then giving square waves the duty factor of which is proportionate to the instantaneous phase shift .DELTA..phi. between the signals R and V, when (2.pi.-1)n<.vertline..DELTA..phi..vertline.<.pi..

Abstract: The invention provides a resistor integrated on a semiconductor substrate and capable of withstanding high voltages. The integrated resistor is formed by a well of the opposite conductivity type relative to that of the substrate and is in the form of a ribbon wound about one of its ends which is connected electrically to a conducting pole. The conducting pole provides the electric connection of the ribbon with the rear face of the substrate and through this substrate.

Abstract: An ultra high frequency circuit constructed in hybrid or integrated form whose parasite capacities are greatly reduced. The ultra high frequency circuit has, besides the components, at least one component fixing metallization and at least one microstrip formed by a metal track, on a first face of a dielectric substrate and, a ground plane metallization on a second face of the substrate. The ultra high frequency circuit is fixed to the base of a case. In order to reduce the parasite capacities formed between metallizations, the second metallized face of the substrate is locally demetallized, in line with the fixing metallization, and an air layer is introduced between the demetallized substrate and the base of the case.

Abstract: A microwave oscillator integrated in a waveguide includes a negative-resistance diode encapsulated in a capped micromodule, a capacitor fixed on the cap, a resonator fixed on the capacitor and a metallic strip fixed on the capacitor and on a grounding stud. The metallic strip constitutes a device for coupling the diode with the auxiliary load and with the resonator. Outside the resonance frequency of the resonator, no oscillation is possible since the diode is in that case loaded by a low resistance and is not capable of oscillating. The dielectric resonator is the only element which resonates, thus endowing the oscillator with high stability.

Abstract: In the invention, the quality of the signal received is improved by symmetrizing the antenna. To this end, this antenna comprises two cords each of which has a symmetry with respect to one and the same plane (XOZ). These cords are linked by their ends to antenna tuning capacitors. The received signal is taken up by a high-frequency line integrated to one of the cords at the connection point of one of the tuning capacitors. Furthermore, the other end of this high-frequency line, arranged in the plane of symmetry, is linked to an impedance amplifier-transformer circuit with a high input impedance.

Abstract: A circuit arrangement for shifting the phase of a signal, in which the signal is applied to two parallel branches where one branch contains a phase-shifting network for purposes of applying a constant phase shift to the signal. A variable amplifier connected in one of the two branches controls the amplitude of the signal and inverts the polarity of the signal. This variable amplifier can be connected in series with the phase-shifting network, or the ampifier can be connected in the branch that is in parallel with the branch containing the phase-shifting network.

Abstract: A split roller bearing assembly includes a bearing body, an endless roller bearing chain mounted on the bearing body, and a plurality of rollers mounted on the chain. The bearing body has a load bearing surface and a return surface which define a path for continuous recirculating movement of the rollers thereabout. The roller bearing chain includes a plurality of pins arranged in a spaced, parallel relationship, and link members connecting the axial ends of adjacent pins together. Each roller is mounted on a corresponding pin of the chain, and is split to define at least two roller components rotatably mounted co-axially to each other on the same pin. Each roller component is rotatable independently of the other roller component of the same pin.

Abstract: The magnetic recording device with rotating head according to the invention comprises a magnetic recording medium, a cylindrical and rotating head, a fixed magnetic excitation circuit; the head comprising, on its surface, two movable pole pieces separated by a gap and each magnetically linked to an initial and a second magnetic circuit in the shape of a portion of a ring and providing a rotating joint to the passage of the magnetic flux, with the fixed, magnetic excitation circuit possessing an excitation coil that induces an magnetic field in a magnetic circuit having two fixed pole pieces, each magnetically coupled by a gap to one of the said rings.Application: Video tape recorders in particular.

Abstract: A linear motion bearing assembly is provided having a pair of aligned shafts which are fastened together, and a pair of bearings which either roll or slide on the aligned shafts. The shafts may be fastened together along a joint formed on their outer surfaces or they may be fastened together with a spacer disposed between the shafts.

Abstract: The present invention concerns a device where the commutation of a luminous beam is ensured by the electrically controlled presence or absence, on the path of the beam, of a fluid causing said beam to be transmitted or reflected. The invention provides for improved decoupling between the output channels of the device, due to the presence of a surface provoking a total internal reflection that allows one to eliminate interference reflections.

Abstract: Size variation of samples subjected to NMR examinations entails the need for calibration of the radiofrequency excitation which gives rise to the resonance phenomenon measured during experiments. Determination of the most suitable value of the radio-frequency excitation amplitude is carried out by scanning the range of potential amplitudes, starting from one end of the range. During the scanning operation, the variation in excitation amplitude varies in a geometrical progression with the order number of the experimentation. It is shown that, by adopting this procedure, determination of the calibrated amplitude is achieved more rapidly while maintaining constant accuracy of determination.

Abstract: The invention provides a connector for flat connections adapted for connecting electrically together printed circuit tracks or printed circuit tracks to a flat cable or two flat cables together. The connector includes a sleeve made from a shape memory material in which the conducting elements intended to be in electric contact are superimposed. The sleeve is adapted for applying transverse forces under the effect of a predetermined temperature so that electric continuity may be provided between these elements.

Abstract: A circuit for calculating the discrete Fourier transform which includes a multiplier, two adders for effecting the calculation of the discrete Fourier transform while describing a butterfly data path, and address processors which supply the multiplier and adders with continuous data under the control of a synchronization clock. To accelerate the calculations, the processor has a memory for reducing the data access time. This memory is divided into two parts, each of which alternately plays the role of calculation memory and input/output memory for the transfer of data with a memory external to the processor.

Abstract: A short channel metal oxide semiconductor transistor device is processed without undesirable short channel effects, such as V.sub.T falloff and with a reasonable source-drain operating voltage support. In a substrate lightly doped with P-type conductivity material and source and drain region heavily doped with an N-type conductivity material, two lightly doped N- regions are disposed between the edge of the gate and the source and drain regions. A channel region is more heavily doped with P-type material than the substrate. Two regions extend from opposite sides of the channel region to an area generally below the two N- regions and above the substrate, which regions are more heavily doped than the channel regions.