MEMS co-vibration combined hydrophone.

• MEMS Co-vibration Combined Hydrophone has excellent cosine pointing and high sensitivity. The precise positioning of weak signals can be achieved. • MEMS microphones are used as scalar channels to avoid the problem of ambiguity of sound positioning on the port and starboard of MEMS Co-vibration Combined Hydrophone. • MEMS Co-vibration Combined Hydrophone has the advantages of low power consumption and low cost. • The microphone is used as a scalar channel to reduce the volume of the MEMS Co-vibration Combined Hydrophone and enhance the concealment of the UUV operation. 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/ μPa) with good cosine directivity. The scalar channel sensitivity is −171 dB @ 1 kHz (re 1 V/ μPa) 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 calculation 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. [ABSTRACT FROM AUTHOR]