A MEMS piezoelectric hydrophone with high sensitivity and wide bandwidth

Abstract To solve the problems of low sound pressure sensitivity and narrow operating bandwidth of hydrophones, this paper proposes a MEMS piezoelectric hydrophone with a corrugated structure substrate. This design is improved from two aspects, on the one hand, the MEMS technology is used to make the aluminum oxide substrate into a corrugated structure, the corrugated structure can make the hydrophone work with better linearity, and at the same time broaden the hydrophone’s operating bandwidth; on the other hand, the array design is utilized to improve the sound pressure sensitivity by integrating four identical sensitive cores in the same piece of hydrophone. The test results show that the sound pressure sensitivity of the MEMS piezoelectric hydrophone of this design is better than −207.6 dB in the operating bandwidth of 10 ∼ 3800 Hz, and reaches the highest −195.5 dB sound pressure sensitivity at the input signal frequency of 2500 Hz.