MEMS co-vibration combined hydrophone

This paper proposes a MEMS co-vibration combined hydrophone (CCH) to position the weak acoustic source of small-volume UUV acoustic self-guided cabins. With an external diameter of 36 mm, it adopts the MEMS triaxial accelerometer to form the vector channel and the MEMS capacitive omnidirectional microphone to form the scalar channel. This paper first analyzes the acoustic receiving model of an elastic-free sphere in water, designs a MEMS co-vibration combined hydrophone packaging and then simulates its acoustic performance. The average density of the encapsulated CCH is 1.01 g/cm3. The vector channel bandwidth is 20 Hz-1,000 Hz, and the sensitivity is-173 dB @ 1 kHz (re 1 V/ mu Pa) with good cosine directivity. The scalar channel sensitivity is-171 dB @ 1 kHz (re 1 V/ mu Pa) with omnidirectional directivity. The error of the orientation test in the standing wave tube is less than 1 degree. The sound source-level test results are mostly consistent with the theoretical calcu-lation based on the actual distance. The above results indicate that the hydrophone can be mounted to UUV to perform sound source detection, which can meet the need for precise positioning, and has a specific application value.

Automated summary

This paper proposes a MEMS co-vibration combined hydrophone (CCH) for precise positioning of weak acoustic sources in small-volume UUV acoustic self-guided cabins. The CCH consists of a MEMS triaxial accelerometer and a MEMS capacitive omnidirectional microphone. The packaging of the CCH is designed based on the acoustic receiving model of an elastic-free sphere in water. The experimental results demonstrate that the CCH can meet the need for sound source detection and has specific application value.