Abstract: A compact omnidirectional antenna for dipping sonar comprises multiple elementary transmission rings formed around a longitudinal axis of the antenna and multiple hydrophones distributed around the longitudinal axis, the antenna intended to be dipped in water, the hydrophones separate from the elementary transmission rings, the hydrophones and the elementary transmission rings fixed in the antenna. The elementary transmission rings and the hydrophones are interlinked along one and the same height (H) measured along the longitudinal axis.

Abstract: A compact omnidirectional antenna for dipping sonar comprises multiple elementary transmission rings formed around a longitudinal axis of the antenna and multiple hydrophones distributed around the longitudinal axis, the antenna intended to be dipped in water, the hydrophones separate from the elementary transmission rings, the hydrophones and the elementary transmission rings fixed in the antenna. The elementary transmission rings and the hydrophones are interlinked along one and the same height (H) measured along the longitudinal axis.

Abstract: An acoustic antenna element for receiving and/or emitting low-frequency underwater waves comprises an acoustic panel formed by at least one acoustic pick-up enclosed in a flexible jacket, the acoustic panel being generally rectangular and being mounted against a curved support by a mounting device including a clamping device comprising at least two flanges the ends of which are mounted on the support, the respective flanges comprising at least one tie between the two ends thereof, and the clamping device capable of adjusting the tension in the ties between the two respective ends thereof, the flanges being arranged so that the support is bent between the two respective ends of the ties and so that the panel is clamped against the support by the ties when they are under tension.

Abstract: An acoustic module is provided for an acoustic antenna for receiving submarine waves, produced in the form of a panel of polychloroprene-based rubber incorporating a plurality of longitudinal tubular ducts extending along the length of the rubber panel and being spaced apart along the width of the rubber panel, the longitudinal ducts receiving columns of hydrophones spaced apart lengthwise, the rubber panel also incorporating at least one transverse duct extending along the width of the rubber panel, the longitudinal and transverse ducts being filled with a fluid and the acoustic panel capable of blocking the ducts in a seal-tight manner, the hardness of the rubber and the thickness of the panel being chosen such that the acoustic module exhibits a first degree of freedom in bending about an axis extending lengthwise and a second degree of freedom in bending about an axis extending widthwise.

Abstract: An acoustic antenna element for receiving and/or emitting low-frequency underwater waves comprises an acoustic panel formed by at least one acoustic pick-up enclosed in a flexible jacket, the acoustic panel being generally rectangular and being mounted against a curved support by a mounting device including a clamping device comprising at least two flanges the ends of which are mounted on the support, the respective flanges comprising at least one tie between the two ends thereof, and the clamping device capable of adjusting the tension in the ties between the two respective ends thereof, the flanges being arranged so that the support is bent between the two respective ends of the ties and so that the panel is clamped against the support by the ties when they are under tension.

Abstract: The invention relates to surface acoustic antennas for submarines. It consists, in a known antenna, in replacing certain pressure sensors with velocity sensors in order to obtain cardioid directivity with a zero oriented toward the hull of the submarine. It allows the use of baffles serving to attenuate the noise generated inside the submarine.

Abstract: The invention relates to surface acoustic antennas for submarines. It consists, in a known antenna, in replacing certain pressure sensors with velocity sensors in order to obtain cardioid directivity with a zero oriented toward the hull of the submarine. It allows the use of baffles serving to attenuate the noise generated inside the submarine.

Abstract: The invention relates to underwater acoustic transmitters intended to be submerged at large depths. It consists in threading the set of annuli forming the transmitter onto an internal tube (303) preferably made from a carbon/resin composite, which supports two end plugs (306, 307) making it possible to relieve the set of annuli of the radial component of the hydrostatic pressure. Furthermore, between the piezoelectric annuli (101) of the transmitter are inserted decoupling annuli (301) which are made as a three-layer structure including a hard and rigid internal layer (201) and two flexible and elastic external layers (202, 203). It makes it possible to increase the transmitting power of these acoustic transmitters.

Abstract: The invention relates to a process for manufacturing a piezoelectric component and to the component resulting from such a process.According to the invention, the manufacturing process comprises the stacking of at least one piezoelectric element (1) and of at least two metallic electrodes (2), each piezoelectric element (1) being inserted between two metallic electrodes (2), characterized in that each piezoelectric element and each metallic electrode is produced, respectively, by coiling a piezoelectric film and by coiling a metallized film.

Abstract: In an acoustic wave reflector working in the sea, a sheet of air is set up between a reflecting plate and a perforated plate. This sheet of air forms a reflecting interface with the reflecting plate. A rubber bladder forms a container which, under the effect of the pressure of the water, feeds the sheet of air through the perforated plate. The thickness of this sheet of air is kept substantially constant up to the limit of submersion of the reflector. This makes it possible to increase the depth at which the acoustic reflectors are used.