【Title】Broadband flextensional transducer with major axis lengthened

【Author】CHEN Si LAN Yu (National Laboratory of Underwater Acoustic Technology, Harbin Engineering University Harbin 150001)

【Abstract】The bandwidth of the Class IV flextensional transducer is narrow for its high mechanical quality factor. For improving its bandwidth performance, a flextensional transducer with major axis lengthened was proposed by the theory of multiple-mode-coupling based on the oval shell. The transducer driven by novel relaxor ferroelectric single crystal lead magnesium niobate-lead titanate (PMNT) was designed and analysed using finite element software ANSYS and a prototype of the transducer was developed. The transmitting voltage response of the transducer reaches to 136 dB with fluctuation 7.8 dB from 1.6 kHz to 16 kHz. Based on the theoretical analysis and experimental results, it proves that the flextensional transducer with major axis lengthened has a much broader bandwidth than the ClassⅣflextensional transducer combing with the advantages of low frequency and high response.