驱动信号对电容式传感器特性的影响分析

在电容检测中，交流电压驱动常常是测量电容变化的必要手段。驱动电压引起作用于可动电极上的静电力，从而影响到可动电极的运动。因此，交流电压的静电驱动势必影响测量的范围和精度。本文详细地分析了由交流电压引起的静电驱动力对微机械结构表态位移特性的影响，并以电容式加速度传感器为例，分单边驱动和双边驱动两种情况，推导出可动电极的运动微分方程。运用近似和图解的方法分另在特殊和一般的情况下求解方程，得到静电驱动电

Analysis of the Effects on the Capacitive Transducer by Driving Signal

Alternative driving voltages are usually needed in measuring the capacitance for capacitive transducers. The electrostatic force caused by the driving voltage affects the dynamic performances of the mechanical structure. Therefore, the performances of the capacitive transducer is affected by the level of the driving voltage. With capacitiv accelerometers as examples, two configurations of singlesided driving, double sided driving are considered. The differential equations are established and solved. Pull in effects as well as the effects on offset displacement, sensitivity, nonlinearity are discussed. Formula and curves and presented that are useful for the analysis and design of capacitive transducers.