Rotation-symmetrical Luneburg lens

摘要

The lens uses materials or a corresponding shape forming, to cause the projected sound velocity on the transmission plane to increase towards a centre of the lens in such a manner that the transmission paths from are focus point, through the lens and towards a point in infinity, are of equal length. The lens may comprise a cylindrical arrangement of lens dishes (1), with a vertical array of sound converters (4) producing a polar response pattern (5) with an azimuthal width determined by the ratio of the wavelength and the horizontal extension, and with a vertical aperture determined by the ratio of the wavelength and the vertical height.