Thomson-csf

Compagnie Europeene De Composants Electroniques Lcc

Jean-Claude Mage

Jean-Luc Rolland

Jean-Paul Castera

Paul L Meunier

Claude Deljurie

Didier Dusclaux

In a magnetic head, there is provided, in the gap, a superconducting material that has zero permeability and prevents the passage of the magnetic field in the gap. Various alternative embodiments are used to improve the efficiency of the head by channelling the magnetic flux outside the gap.

Magnetic recording/playback head comprising a superconducting material

A low-noise oscillator includes a resonator constituted by a coil, a capacitor and a sustaining coil which are made of superconductivity material and maintained at a low temperature below the critical temperature; a linear amplifier which always operates in its linear zone; and a load. The amplitude of oscillation is stabilized when it has attained a threshold value such that the superconducting material constituting the coil of the resonator becomes progressively resistive under the action of the magnetic field produced by this coil. The coil then dissipates part of the energy injected into the resonator. Since the high-frequency noise of the oscillator is essentially determined by the low-frequency noise of its nonlinear element, the use of superconducting material at low temperature in order to constitute the nonlinear element makes it possible to obtain an oscillator having very low noise.

Low-noise oscillator using superconducting nonlinear element

A method of making a flat magnetic structure having coils thereon, said structure including magnetic read/write heads using a flat substrate that has at least one side made of a magnetic material, said method including the steps of:initial machining of the magnetic side of the substrate to form supporting means for conducting wires, which forms said coils, and to demarcate future magnetic poles of said magnetic read/write heads; then depositing, on either side or both sides of the substrate, connecting pins at a rate of two pins per said coil; then positioning the conducting wires on said supporting means to form the coils; then connecting the ends of the conducting wires of each coil to the corresponding connecting pins; then coating the machined magnetic side with an insulating material; and then machining and polishing the coated side until the magnetic poles are exposed.

Method for making a flat magnetic structure for read/write magnetic heads

The invention provides electromagnetic resonators and high frequency filters constructed from these resonators which are formed by parallelepipeds made from a dielectric material, each of these parallelepipeds being covered with at least two metalizations disposed parallel to the direction of movement of an electromagnetic wave.

Twin strip resonators and filters constructed from these resonators

A dielectric material having a high dielectric constant, very low high-frequency losses and very high temperature stability is prepared in particular by sintering previously ground raw materials in an oxidizing atmosphere at 1450.degree. C. The molar composition of the raw materials is as follows: t, TiO.sub.2 ; x, SnO.sub.2 ; y, ZrO.sub.2 ; a, NiO; b, La.sub.2 O.sub.3 ; where t is between 0.9 and 1.1, x is between 0.1 and 0.4 moles, y is between 0.6 and 0.9, a is between 0.015 and 0.06 moles, b is between 0.01 and 0.1 moles with an addition of iron of 0.0035 mole in respect of one mole of TiO.sub.2 obtained, for example, from the use of steel equipment for the grinding operation. When x is in the vicinity of 0.35, the coefficient of thermal variation .tau..sub.f is reduced to zero and the quality criterion Q.f is high.

Growing community of inventors

Levallois Perret, France

Jean-Claude Mage