A High-Power and High-Efficiency Bender Transducer

Over the past several years,Hangzhou Applied Acoustics Research Institute (HAARI) hasdeveloped the ring transducer,including the air-backed ring transducer(ABRT) and free-flooded ring transducer(FFRT). Previous papers[1][2] described a kind of monostatic ABRT with radially poled ceramic and a broadband monostatic segmented FFRT with tangentially poled ceramic.In order to meet the requirements of small-sizedness,high-power,and high-effciency requirements,HAARI conducted in-depth research on bender disk transducers(BDT).The BDT described in this paper was potted in polyurethane,with a mass of 4.3kg in air.Tt has a maxium diameter of 190 mm.Both projector and hydrophone operation are available.The measured maximum transmitting voltage response(TVR) is 139.1dB//μPa @1m/V,@1.43kHz and the quality factor (Q) is 6.5. The maximum sound pressure level(SPL) is greater than 204.1dB. But in practice the output power of the power-amplifier is small,so the measured SPL is 201.8 dB,and for this measurement was tested at a water depth of 31 m. The acoustic output efficiency at resonance is 93.3% if we assumed the directivity index(DI) is 0.The maximum of the Receiving Voltage Response (RVS) in free field is -156.9dB//V/μPa@1.53kHz.The frequency band with receiving response decreasing 3dB is from 1.4kHz to 1.6kHz.The transducer is robust enough to withstand hydrostatic pressure at 4.5 MPa.