Undersea acoustic antenna with surface sensor
AssigneeThomson-CSF
InventorsBernard Fromont, Robert Fichaux
Life of this patent
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Abstract
An acoustic antenna includes at least one surface sensor formed by a stack of conducting materials and dielectric layers of piezo-electric material enclosed in a sheathing of flexible material. The assembly forms a flat panel 2 mounted against the hull 5 of a navel vessel and takes the shape of the hull. The mounting of the panel on the hull is achieved by two streamlined edging sections 3, 4 while leaving an intermediate water layer 6 remaining between the panel 2 and the hull 5. The sheathing includes an envelope of flexible material filled with a visco-elastic lining material and the piezo-electric material of the dielectric layers of the sensor is preferably a polyvinylidene fluoride film.
Claims10
An acoustic antenna structure for receiving low-frequency undersea waves, said structure including at least one surface sensor formed by a stack of conducting layers forming electrodes and of dielectric layers of piezoelectric material interposed between these conducting layers, said sensor being enclosed in a sheathing of flexible material, the assembly thus constituted forming an attached flat panel mounted against a wall of a hull of a naval vessel said panel exhibiting a degree of freedom in bending so as to allow it to follow the shape of this hull, characterized in that the panel is mounted on the hull while leaving an intermediate water layer between panel and hull, the thickness of this water layer being such that the distance separating the wall of the hull from a mid-plane of the sensor is less than a quarter of the wavelength of the maximum frequency of the operating band of the sensor in order to avoid destructive interference between said waves and said hull.
Dependencies are inferred from the claim text.