The design of transducers and arrays for underwater data transmission

Consideration is given to 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 author introduces the underlying physics of sound propagation in solid-bar and disc structures typically used for manufacturing underwater acoustic transducers. The variability 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. An examination is made of several specific designs, including thin-disc and broadband high-frequency transducers as well as piston and tonpilz structures modified electrically and mechanically to produce broad, controlled passband responses. A variety of more exotic structures is also included. Attention is given to arrays of transducers and, particularly, to the problems involved in overcoming element interaction and inadequacies in element behavior