Abstract: A cable comprising a central armour, a dielectric helically grooved core and an optical fibre housed in each one of the plurality of the grooves is produced by extrusion of the profiled core on the armour, pulling vertically the core through an annular laying unit comprising a plurality of take off reels supplying optical fibre guiding each of said fibre within one of the grooves by mechanical and pneumatic means and taping fibre filled core.

Abstract: A cable comprising a central armour, a dielectric helically grooved core and optical fibres housed in said grooves which are formed with a lip protruding from one edge is produced by extrusion of the profiled core on the armour heating of the core, laying of one fibre within one groove with the aid of a fibre guide controlled by a positioning slot in said core, bending the lip to close the groove outwardly and repeating said heating, laying, etc. . . for each fibre and taping the structure.

Abstract: In a surface wave isolator consisting of two gyromagnetic slabs a conductive strip between said slabs, means to establish a magnetizing field within said slabs, a two part load is associated side by side with said slabs and the strip extends also between the two parts of the load. A first part of the load is a continuous load parallel to the strip, a second part of the load is a plurality of localized absorbing means placed along the propagation axis and parallel to said strip. The impedance of the localized absorbing means is matched to the impedance of an unwanted parasitic propagation mode at the corresponding place.

Abstract: High precision film resistors are designed as a main resistive element corresponding to half the total value associated with five additional resistive elements the values of each of which are successively half of the value of the preceding one plus one resistive element of the same value as the smallest element of the five above mentioned elements, each of the additional element is originally short-circuited, adjustment being performed by cancelling at least one of the short circuits. This design of the resistive elements allows a reduced number of short circuit suppressions than previously used designs with the same precision.

Abstract: In a microwave cylindrical heating TM.sub.010 cavity for continuous heating of rods, wires, etc. . . focussing means are provided surrounding the entry and or the exit to locally concentrate the microwave energy on the object to be heated. Said means consists in 45.degree. annular wedge. As variants focussing is achieved by ferromagnetic annulus.

Abstract: A frequency translator, for translating a signal at frequency f into the F-f and F+f bands where F is a carrier, consisting mainly of an integrated circuit comprising two bidirectional switches controlled by two 180.degree. out of phase square signals at the carrier frequency, each switch being supplied from one output of a d.c. voltage source fed with said carrier equal respectively to the absolute maximum and minimum values of the square wave, said signal being applied to said bidirectional switches either directly or through a transformer. In a preferred embodiment the switches consist of a C-MOS integrated circuit.

Abstract: A low reverse current gold barrier Schottky diode is produced by introduction of a highly reducing metal layer between the substrate and the gold layer through which the gold is diffused to contact the substrate. As such reducing metal, chromium gives good results.

Abstract: The anodization of sintered anodes for tantalum capacitors is carried out in two successive steps separated by a cleaning step in an acid bath. In a preferred variant of the process both the first anodization and the cleaning are performed on batches of anodes which are individually sorted and mounted on current carrying bars before the second anodization step. The direct leakage current of capacitors made from anodes anodized according to the invention is substantially lower than that of capacitors with prior art anodes. The capacitors are also less sensitive to temperature.

Abstract: In solid electrolytic tantalum capacitors, the dielectric consisting mainly of tantalum pentoxide contains two different ionized additions the valences of which are respectively higher and lower than 5.

Abstract: A cable comprising a disc insulated coaxial structure in which said discs are designed with notches in which are located optical fibres extending parallel with the inner conductor of the coaxial structure. An insulating keeper wire is forced into the notch to prevent the free fibres escaping therefrom. One or several fibres are contained within each notch.

Abstract: In solid tantalum electrolytic capacitors, an additive is introduced in the oxide dielectric layer consisting of an ion with a valency different from 5 in a concentration variable across the thickness of the layer. The nature of the additive is selected according to the characteristic to be improved.

Abstract: In an electromechanical filter comprising longitudinally vibrating resonators intercoupled by means of longitudinally vibrating rods, the transducers each consist of two halves located on two flats machined on the same outermost resonator along two parallel planes.

Abstract: Improved anodes for solid electrolytic capacitors are produced by introducing in the anode body made of a film forming sintered metal powder one of the following additives : tungsten, molybdenum, vanadium and hafnium, at the most suitable step of the manufacturing process previous to sintering under one of the following forms : pure metal, oxide, sulphide. In a preferred embodiment the additive is introduced in the binder used for pelletizing. In another embodiment the additive is introduced by dipping the presintered anodes in a solution containing said additive.

Abstract: A system for quality checking of a digital connection circuit using a telephone line. Its principle resides in alternately and repetitively transmitting a check message followed by a quality character from one to the other of two similar equipments respectively located at the ends of the circuit. The quality character takes account of the results of the checking effected by the corresponding equipment when it receives the last previously transmitted check message. The latter message further includes a n times repeated synchronization character and a pseudo-random series of p binary signals and is immediately followed by a quality character which is stored and displayed by the receiving equipment which operates at the considered time.

Abstract: A wafer type millimetric crystal holder of the Sharpless type with an impedance matched i.f. coaxial output. The connection between the i.f. coaxial output and the diode comprises two coaxial quarter wavelength stubs interconnected by a strip line element with a wire central conductor operating as a rejector at the carrier frequency. The diameter of the central conductor is determined by the impedance matching condition.

Abstract: In an electromechanical filter made of longitudinally vibrating cylindrical metal bars connected through bending vibrating coupling rods, the coupling rods are connected to one of the end faces of said resonators. A plurality of resonators are connected to a unitary rod.

Abstract: Demodulator for phase modulated carrier pulse signals or phase codes in which the pulses are coded according to a plurality of N phases of the carrier. It comprises a digital phase lock loop system for locking to a frequency equal to N times the carrier frequency which includes at least a two input phase detector, a loop integrator and a voltage controlled oscillator having an output connected to the first input of the phase detector, means for dividing by N the frequency of this oscillator and for generating a reference carrier signal. The phase codes are decoded by comparing the phases of the carrier of the phase codes to the phase of the reference signal. In order to derive from all the phase codes a train of synchronous pulses a multiphase shifter receives the carrier of the phase codes and locally generates a plurality of carriers having phase shifts equal to 0, 2.pi./N, 2.times.2.pi./N, . . . ([N/2]- 1) .times.2.pi.

Abstract: A high level broadband VHF isolator using surface propagation made of the waves comprises two gyromagnetic slabs on both sides of a planar metal sheet acting as a double mode transformer or wave launcher between the two terminals of the isolator and the gyromagnetic medium and magnetizing means. The width of the mode transformer is smaller than that of the slabs and radiating slots are provided along at least one side parallel to the propagation direction. The magnetizing field value corresponds to the gyromagnetic resonance at the mid-frequency of the operating band in the neighborhood of the slots and lower elsewhere. Magnetic means are provided to compensate for the temperature variation of the ferrite properties.

Abstract: A broadband slot line non reciprocal microwave device which comprises a matched load placed on the face of a ferrite plate which is located within the microwave magnetic field of the slot line, said face being opposite to said slot and designed so that its height is larger than 3 times the width of the slot and its length is at least equal to a half wavelength as propagated within the slot at the maximum operating frequency. Said matched load may be a second slot line or a lossy ferrite plate. The device operates as an isolator with more than 20 dB isolation. It can be designed as a four port circulator.

Abstract: A process for establishing gold contact studs on thin film circuits consists in localized sublayer deposition of a platinum-gold alloy followed by subsequent electrolytic gold thickening of the studs. The studs so produced are particularly fit for thermocompression interconnection.