电容式振动微机械陀螺接口电路的设计、模拟与测试

【作者】 黄小振；

【导师】 王跃林；

【作者基本信息】 中国科学院上海冶金研究所 ， 微电子学与固体电子学， 2001， 硕士

【摘要】 振动式微机械陀螺具有微型化、可集成和批量生产等优点，在航空航天、武器装备、汽车工业、医疗仪器等领域具有广泛的应用前景。对于电容式微机械陀螺，检测电容的变化多在aF量级，这对陀螺信号检测电路提出了很高的要求；本论文针对静电梳齿驱动电容检测微机械陀螺的接口电路进行了深入研究。 首先，根据振动式微机械陀螺的动力学方程，建立了其等效的电学模型；通过模拟，分析了陀螺灵敏度和带宽等性能，并优化了陀螺的工作参数，比如驱动频率、模态匹配电压等。 接着，设计了电容式振动微机械陀螺的接口电路，其中包括驱动和检测电路两个部分。在驱动电路的设计中，设计了外加交流信号驱动和自激驱动两种形式的电路，并结合陀螺的驱动等效电学模型对自激驱动进行了模拟，验证了其可行性。在陀螺检测电路的设计中，为了实现传感器和接口电路的整体模拟，根据振动式微机械陀螺等效的电学模型，建立了其检测电容模型；并对设计的检测电路进行了模拟，优化了检测电路中的模块增益、滤波带宽、相位移动等参数。 根据优化的参数制作了陀螺的接口电路，利用这个电路对微机械可变电容器进行了测试，测试结果表明所设计的检测电路至少可以检测40 aF电容的变化幅度。更多还原

【Abstract】 Micromachined vibratory gyroscope has been studied widely and deeply for its unique advantages and broad applications. In this dissertation, we designed, simulated, and tested the interface circuit of the vibratory gyroscope, which is driven by electro- static comb finger forces and detected by capacitance. From the theoretical analysis of the micromachined vibratory gyroscope, we derived its equivalent electrical analogue, which was simulated in PSpice to study the performances of the gyroscope, and obtained its optimized parameters, such as the driving frequency and the voltage for the mode matching. The interface circuit was devided into two parts, one is the driving-circuit and the other is detecting-circuit. Two types of driving-circuit were designed, which are the external applied voltage drive and the self-drive. We simulated the self-drive circuit in PSpice using the equivalent electrical analogue and verified its function. Circuit for detecting the tiny capacitance variation was designed for the detecting-circuit of capacitive micromachined vibratory gyroscope. We proposed the analogue of the gyroscope detecting-capacitance in PSpice, and simulated the detecting-citcuit using the analogue. From the simulation, we optimised the circuit parameters, such as the gain, the filter bandwidth, etc. The system resolution was also obtained from the circuit noise analysis in PSpice. The PCB of the interface circuit was implemented. From the measurement of a micromachined variable capacitor using the interface circuit, we found that the resolution of the circuit was 40 aF.更多还原