Broadband cluster transducer for underwater acoustics applications

A broadband cluster transducer, based on barrel-stave flextensional transducer technology, was designed, built, and tested in air and seawater at Defence R&D Canada-Atlantic. The design goal was to develop a transducer that exhibited a transmitting voltage response of greater than 120 dB1 microPa-m/V from 1 to 7 kHz and have the potential for beamsteering. Six orthogonal piezoceramic-driven class I barrel-stave transducer elements mounted on a central manifold were wired separately, allowing each to be driven individually or in combination with the other elements. The resonance modes under the following drive conditions were determined from in-air conductance measurements: each of the six elements excited individually as mass-loaded class I flextensionals, three collinear pairs driven separately as class III flextensionals, and all six elements driven in phase simultaneously. The fully-driven cluster was found to have a transmitting voltage response of greater than 120 dB1 microPa-m/V from 800 Hz to more than 10 kHz and its topology is amenable to beamsteering that is yet to be characterized.