Wideband Single Crystal Longitudinal Transducer for Underwater Sound

The piezoelectric single crystal has significant advantages including both high electromechanical coupling and piezoelectric coefficients. By use of four 33-mode single crystal pieces, a thin light beryllium alloy head mass and a thick heavy tungsten alloy tail mass can expand the bandwidth of the middle-frequency transducer. The one-fourth finite element model of transducer was set up with ANSYS software and the structure of the transducer was optimized. A final 9-element array was designed, fabricated and measured. The bandwidth of the array is 12kHz-40kHz, in which the ripple of the transmitting voltage response does not exceed +/-3.3dB. There are several conclusions from the research: the bandwidth of tonpilz transducers can be expanded by the use of single crystal pieces, beryllium alloy head mass and tungsten alloy tail mass; and it gives a method to achieve the broad-band projecting performance of middle-frequency transducers.