通风孔对压电麦克风低频响应的影响研究

Effects of Vents on the Low Frequency Response of Piezoelectric Microphones

根据压电麦克风的工作原理建立压电传感器的集总元件等效声电模型,分析通风孔结构对压电麦克风灵敏度的影响。通过有限元建模,研究通风孔的几何尺寸对压电麦克风低频输出的影响。通风孔位于硅基的位置不影响麦克风的低频输出。通风孔的横截面积一定时,长度越长,低频响应越快。通风孔的长度一定时,横截面积越小,低频响应越好。如果要达到相同的低频位移输出,通风孔的横截面积比为2倍时,长度比应为4倍。

According to the working principle of piezoelectric microphones,the equivalent lumped element acoustic electric model of a piezoelectric sensor was established,and the influence of the vent structure on the sensitivity of the piezoelectric microphone was analyzed.Through finite element modeling,the effects of the vent’s geometrical sizes on the low frequency output of the piezoelectric microphone were studied.The locations of ventilating holes at different positions of the silicon base have no effect on the low frequency output of the microphone.When the cross sectional area of the venting holes keeps constant,the longer the vents length,the higher the low frequency response.When the length of the vent keeps constant,the smaller the cross-sectional area,the better the low-frequency response.When the cross-sectional area ratio of the vent holes is 2,if the same low-frequency displacement output is to be achieved,the length ratio should be 4.