A deep-sea and low-frequency spherical vector hydrophone with high sensitivity

Abstract In this work, we report on the design optimization of a deep-sea and low-frequency spherical vector hydrophone with high sensitivity. Piezoelectric accelerometers and a pressure-resistant shell are applied to achieve optimal performance. The underwater electro-acoustic performance of the vector hydrophone is investigated using the finite element simulation. A hydrophone prototype is fabricated using titanium alloy for the shell and PZT-5H piezoelectric materials for the accelerometers. Measurements show that the hydrophone exhibits an overall sensitivity of −169 dB re 1 V μPa −1 at a low frequency of 300 Hz and that its receiving directivity has a cosine pattern. Moreover, a pressure test supports the deep-sea functionality of the hydrophone 6000 m underwater.