Design, fabrication and testing of a high frequency broadband hydroacoustic transducer for sonar systems

Abstract

A high frequency broadband hydroacoustic transducer was fabricated for applications such as small target detection and fine imaging in sonar systems. The utilization of the structure design of multimode coupling theory is employed to expand the operational bandwidth of the transducer by leveraging the characteristics of 1–3 type piezoelectric composites that possess a broad frequency range. Piezoelectric composite sensitive elements of varying thicknesses were developed through optimization of dimensional parameters using theoretical and finite element simulation analyses. These composite sensitive elements were then bonded to a spiral stepped backing to enable lateral stacking, ultimately resulting in the fabrication of a high frequency broadband hydroacoustic transducer. The outcomes of the underwater performance evaluation indicate that the transducer's central frequency is 310 kHz, with a −3 dB bandwidth capable of reaching 100 kHz. The maximum transmit voltage response is 159 dB, while the maximum receive sensitivity is −182 dB. Additionally, the directional beam opening angle of −3 dB at the center frequency is roughly 9°, which effectively broadens the transducer's bandwidth.