THE DESIGN OF TRANSDUCERS AND ARRAYS FOR UNDERWATER DATA-TRANSMISSION

This paper is concerned with the design of underwater acoustic projector transducers for communication purposes. Particular interest is focused upon broadband designs which provide the potential for high data-rate communication. The paper introduces the underlying physics of sound propagation in those solid-bar and disc structures typically used for manufacturing underwater acoustic transducers. The variablity of sound speed with bar dimensions, in bar resonators, is discussed. Consideration is given to the nature and identification of different modal states in such structures. The possibilities and limitations in modeling and design are reviewed. The paper then considers several specific designs, including thin-disc and broadband high-frequency transducers as well as piston and tonpilz structures modified both electrically and mechanically to produce broad, controlled passband responses. A variety of more exotic structures that may interest the experimentally inclined reader is also included. Finally, attention is turned to arrays of transducers and, particularly, to the problems involved in overcoming element interaction and inadequacies in element behavior.