Abstract: An assembly comprising a device and an obstacle subjected to an incident electromagnetic wave of wavelength ?. The obstacle is formed from an electrically conductive material and has a substantially cylindrical shape of transverse dimensions r with respect to a longitudinal axis (O, ez). The longitudinal axis is substantially perpendicular to a propagation direction of the incident electromagnetic wave. The obstacle further has a maximum transverse dimension d such that the ration ?/d is less than 1. The device is placed on all or a part of a surface of the obstacle and comprises a sleeve with a dielectric coating of equivalent relative permittivity EREQ, of height hP along a longitudinal axis of the sleeve, substantially equal to formula A, and a sleeve with an electrically conductive coating placed on the periphery of the dielectric coating.

Abstract: A device for protecting from lightning (30) is intended to form at least a portion of an external surface of a structure to be protected and comprises a ground plane (32), a dielectric substrate (34) arranged on the ground plane, and an array of first metal elements (36) arranged on the dielectric substrate (34) and extending substantially parallel to the ground plane (32) in such a way that any pair of consecutive elements from said first metal elements (36) is separated by a distance comprised between 0.01 millimetres and 10 millimetres, said first metal elements being distributed in juxtaposed similar patterns, each of said patterns including first metal elements of different dimensions corresponding respectively to different electromagnetic resonant frequencies the juxtaposition of which defines an electromagnetic absorption band of the pattern.

Abstract: An assembly comprising a device and an obstacle subjected to an incident electromagnetic wave of wavelength ?. The obstacle is formed from an electrically conductive material and has a substantially cylindrical shape of transverse dimensions r with respect to a longitudinal axis (O, ez). The longitudinal axis is substantially perpendicular to a propagation direction of the incident electromagnetic wave. The obstacle further has a maximum transverse dimension d such that the ration ?/d is less than 1. The device is placed on all or a part of a surface of the obstacle and comprises a sleeve with a dielectric coating of equivalent relative permittivity EREQ, of height hP along a longitudinal axis of the sleeve, substantially equal to formula A, and a sleeve with an electrically conductive coating placed on the periphery of the dielectric coating.

Abstract: A device for protecting from lightning (30) is intended to form at least a portion of an external surface of a structure to be protected and comprises a ground plane (32), a dielectric substrate (34) arranged on the ground plane, and an array of first metal elements (36) arranged on the dielectric substrate (34) and extending substantially parallel to the ground plane (32) in such a way that any pair of consecutive elements from said first metal elements (36) is separated by a distance comprised between 0.01 millimetres and 10 millimetres, said first metal elements being distributed in juxtaposed similar patterns, each of said patterns including first metal elements of different dimensions corresponding respectively to different electromagnetic resonant frequencies the juxtaposition of which defines an electromagnetic absorption band of the pattern.

Abstract: A high-impedance passive device to radio-electrically decouple two antennas operating at least partially within a common frequency band and arranged on a surface of the carrier structure. A substrate of the device has a flexible dielectric material layer having a predetermined thickness with patches of conductive material arranged on its surface and a layer to attach the device onto the surface of the carrier structure. The patches having predetermined shape and arrangement. The body of the substrate separates the dielectric layer from the surface of the carrier structure. The substrate thickness is determined based on the size, number, and arrangement of the patches, and further it is based on the aerodynamic constraints imposed on the device. The device having an impedance to cause the desired decoupling in the common frequency band.

Abstract: A high-impedance passive device to radio-electrically decouple two antennas operating at least partially within a common frequency band and arranged on a surface of the carrier structure. A substrate of the device has a flexible dielectric material layer having a predetermined thickness with patches of conductive material arranged on its surface and a layer to attach the device onto the surface of the carrier structure. The patches having predetermined shape and arrangement. The body of the substrate separates the dielectric layer from the surface of the carrier structure. The substrate thickness is determined based on the size, number, and arrangement of the patches, and further it is based on the aerodynamic constraints imposed on the device. The device having an impedance to cause the desired decoupling in the common frequency band.

Abstract: The invention pertains to a method for assigning communication resources in a telecommunication system, in which the communications are relayed by satellites covering an area of land that is divided into zones. Each zone has a communication resource pattern formed, on the one hand, by the directions of the satellites seen from the zones and, on the other hand, by frequency sub-bands and/or polarization. These resources are distributed so that two adjacent zones comprise different resources. The patterns of two zones are distinguished only by the direction of the satellite(s) that are assigned to the zones having this pattern. In one embodiment, all of the frequency resources are assigned to all the zones and the patterns are only distinguished by the directions of the satellites that supply these resources.

Abstract: The invention relates to a telecommunication method using a constellation of terrestrial satellites in which remote terminals communicate via a plurality of satellites communicating via direct links. The method is characterized in that the constellation of satellites has at all times a track on the Earth consisting of a single curve (26) and in that communications are transmitted from one satellite to another along the single curve. The constellation is a Walker constellation, for example.