In this paper, a novel dual-mass MEMS piezoelectric vector hydrophone is proposed to eliminate the transverse effect and solve the problem of directivity offset in traditional single-mass MEMS piezoelectric vector hydrophones. The reason for the directional offset of the traditional single-mass cantilever MEMS piezoelectric vector hydrophone is explained theoretically for the first time, and the angle of the directional offset is predicted successfully. Both analytical and finite element methods are employed to analyze the single-mass and dual-mass cantilever MEMS piezoelectric vector hydrophone. The results show that the directivity of the dual-mass MEMS piezoelectric vector hydrophone has no deviation, the transverse effect is basically eliminated, and the directivity (maximum concave point depth) is significantly improved, so more accurate positioning can be obtained.
Keywords: concave point depth; directional offset; directional offset angle; dual mass.