Development of a broadband underwater sound projector

Abstract

An underwater sound projector has been developed for operation over a decade long frequency range. The output of the projector has been designed for 10 kHz to 100 kHz operation on an autonomous underwater vehicle (AUV). The transducer is resonant at 100 kHz but has been designed to deliver high sound pressure levels without impedance or phase instabilities. The transducer features the first successful stacking of 1-3 piezocomposite materials. The selection of the 1-3 piezocomposite materials has resulted in the mode-free sound output while the stacking arrangement permits acoustic operation with twice the sound output at half the resonance frequency of a single layer. The stacking is done mechanically in series and electrically in parallel with the center electrode as the positive plane. Furthermore, the center electrode has been segmented into four individual elements such that combinations of the sectors offer the ability to access nine different apertures.