High Sensitivity Electret Accelerometer With Integrated FET
High Sensitivity Electret Accelerometer With Integrated FET
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DOI：
10.1109/jsen.2014.2302300
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发表时间：
2014-06-01
影响因子：
4.3
通讯作者：
Sessler, Gerhard M.
中科院分区：
文献类型：
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作者：
Hillenbrand, Joachim;Motz, Tilman;Sessler, Gerhard M.
介绍了一种高灵敏度、低等效噪声级的驻极体加速度计。采用集成场效应晶体管作为高阻抗电压放大器。该电压是在金属地震质量和背板之间产生的，由带电的驻极体薄膜覆盖。这两个电极由一个柔软的多孔聚合物环隔开。在施加外部加速度时，地震质量的惯性力改变了环的厚度，从而改变了电极的距离。用驻极体加速度计测量的灵敏度高达600 mV/g，等效噪声电压低至80微克。具有平坦频率响应的高质量加速度计可以在气隙体积完全封闭或开放的情况下获得。对于这两种实现方式，假设不存在阻尼风流动效应，都给出了一个分析模型。讨论了这两种模型的变型，并将模型的计算数据与在细胞间隔环上施加不同内部静压的加速度计的测量结果进行了比较。
Electret accelerometers with high sensitivity and low equivalent noise level are presented. An integrated field effect transistor is used as a high impedance voltage amplifier. The voltage is generated between a metallic seismic mass and a backplate, covered by a charged electret film. These two electrodes are separated by a soft cellular polymer ring. Upon application of an external acceleration, the inertial forces of the seismic mass change the thickness of the ring and thus the distance of the electrodes. Sensitivities of up to 600 mV/g and equivalent noise voltages as low as 80 mu g were measured with the electret accelerometers. High quality accelerometers with flat frequency responses can either be obtained with completely closed or opened air gap volumes. For each of these two implementations, an analytical model is presented, assuming the absence of damped air streaming effects. Both model variants are discussed and calculated data from the models are compared with measured results obtained with an accelerometer operated with various internal static pressures on the cellular spacer ring.