Underwater transducer and projector therefor

摘要

An underwater transducer having both projector and hydrophone elements utilizes a new technique permitting the annular projector rings of a given piezoelectric material and resonant frequency to be tailored in diameter to accommodate various requirements, such as a need for more interior space. Where the projector rings can be expanded to the diameter of an accompanying hydrophone array, this makes possible a more compact and, in particular, a shorter structure than has been used for transducers of similar capability before. In the transducer the projector rings are positioned axially along a central support tube alternating with the hydrophones arranged in annular groups. Each projector ring is formed of a plurality of segments of alternately active material and inactive material having a sound velocity differing from (usually faster than) that of the active material. Thus the diameter of the annular elements for a given active material and a desired resonant frequency may be varied since the resonant frequency is related to the velocity of sound in the composite material used in the elements.