Commissariat &#xc0; L'&#xc9;nergie Atomique Et Aux &#xc9;nergies Alternatives

Commissariat a L'energie Atomique

Axalto S.a.

Elekta Neuromag Oy

Myriam Pannetier

Claude Fermon

Béatrice Bonvalot

Nicolas Biziere

Juha T Simola

Thierry Sollier

Francois Vacher

François Vacher

A protected electrical device having at least one electrical sub-assembly () to be protected comprises on at least one () of upper and lower surfaces (), at least a screening layer () against the electromagnetic (EM) and radiofrequency (RF) fields emitted by the electrical sub-assembly (). The screening layer () comprises at least a first layer made of soft magnetic material with a high relative permeability (&micro;r) larger than 500. The screening layer () is placed on substantially the whole surface of said at least one () of the upper and lower surfaces (), except on predetermined regions () of limited area, the electrical connections () with external devices being located on at least some of the predetermined regions of limited area.

Screened electrical device and a process for manufacturing the same

A device for non destructive evaluation of defects in a metallic object () by eddy currents, comprises a field emitter () for emitting an alternating electromagnetic field at a first frequency fi in the neighborhood of the metallic object (), and a magnetoresistive sensor () for detecting a response signal constituted by a return electromagnetic field which is re-emitted by eddy currents induced by the alternating electromagnetic field in the metallic object (). The device further comprises: a driving circuit () for driving the magnetoresistive sensor () by a current at a second frequency fc which is different from the first frequency fi, so that the magnetoresistive sensor () acts as an in situ modulator; a detector for detecting a response signal between the terminals of the magnetoresistive sensor (); a filter for filtering the response signal detected by the magnetoresistive sensor () to keep either the frequency sum (fi+fc) of the first and second frequencies or the frequency difference (fi&#x2212;fc) of the first and second frequencies, and a processor for processing the filtered response signal and extract eddy current information on defects in the metallic object ().

Method and device for non destructive evaluation of defects in a metallic object

The device for measuring magnetic field by using a magnetoresistive sensor comprises at least one magnetoresistive sensor (), a module () for measuring the resistance of the magnetoresistive sensor (), a generator module () for generating an additional magnetic field in the space containing the magnetoresistive sensor (), and a control unit () firstly for selectively controlling the generator module () to apply an additional magnetic field pulse possessing a first value with first polarity that is positive or negative and magnitude that is sufficient to saturate the magnetoresistive sensor (), and secondly for selectively controlling measurement of the resistance of the magnetoresistive sensor () by the module () for measuring resistance.

Method and apparatus for magnetic field measurements using a magnetoresistive sensor

For protecting a circuit () against a mechanical or electromagnetic attack, an active protection device attached to the circuit comprises: &#x2014;at least one generator () for generating a magnetic field, &#x2014;at least one magnetic sensor S, S, S, Sfor measuring a value of the magnetic field, &#x2014;an integrity circuit connected to the at least one magnetic sensor S, S, S, Sand to the circuit (). The integrity circuit activates a reaction procedure in the circuit if the measured value of the magnetic field made by the magnetic sensor is out of a values domain, the values domain being correlated to the generated magnetic field.

Active protection device for protecting circuit against mechanical and electromagnetic attack

The device for sensing a RF field comprises a flux-receiving loop () including a circumferential path having a defined path width (d), the flux-receiving loop () having a portion () that transforms the magnetic flux flowing through the flux receiving loop () into a high magnetic field. The portion () comprises a constriction of the flux-receiving loop () that concentrates the current lines in the circumferential path to define a current-field transformer. At least one very low noise magnetic field transducer () is located at a very close distance from the constriction.

Device for sensing RF field

The device for sensing a magnetic field comprises a closed superconducting pick-up loop () having a path width (d) etched out of a single layer superconducting thin film and provided with a constriction () having a width (w) of narrow dimension smaller than the path width (d). The closed superconducting pick-up loop () constitutes a flux-to-field transformer (FFDT). At least one magnetoresistive element () is placed on top of or below the superconducting thin film, is isolated from the superconducting thin film by a thin insulating layer and is located so that an active part of the magnetoresistive element () is at the location of the constriction () and has a width equal to or less than the width of the constriction (). The active part of the magnetoresistive element () is oriented so that the bias current in this active part is directed essentially along the constriction (), orthogonally to the width of narrow dimension.

Growing community of inventors

Bures sur Yvette, France

Myriam Pannetier