Thin, lightweight, low frequency acoustic projectors for shallow water environments

Miniature flextensional transducers, called cymbals, have been incorporated into thin, lightweight, large area panels for use as low frequency acoustic projectors in shallow water. The prototype panels, measuring 100-mm by LOO-mm by 6.35-mm thick exhibit a high acoustic output at a relatively low in-water resonance frequency. Furthermore a second resonance frequency that is over an order of magnitude higher suggests that the panel may be used to provide sound output over almost a two decade frequency band. The mass of the unpotted panel is less than 150 grams and the total thickness is 6.35 mm. The cymbal panels are believed to be excellent candidates as acoustic projectors on autonomous and/or unmanned underwater vehicle platforms as well as other shallow water platforms where low frequency, light weight and high acoustic output are desired.