A low-noise MEMS acoustic vector sensor

摘要

A low-noise micro-machined acoustic vector sensor is presented. It is desirable that the application of difference capacitance principle combined with bulk micro-machining silicon process techniques may improve the low frequency sensitivity and dynamic range of the acoustic vector sensor as well as its miniaturization. The microstructure of the hydrophone was fabricated by MEMS technology, and measured by underwater standing wave field. The experiment results show that the acoustic vector sensor has good low-frequency characteristic, the free-field pressure sensitivity is −179.9 dB (dB re 1V/µPa) at 1000 Hz with a about 2 dB one-third octave positive slope over the 20∼2000Hz frequency response range, and the dynamic range reaches to 120 dB (100Hz BW).