【作者】 许金海；

【导师】 冯勇建； 胡国清；

【作者基本信息】 厦门大学 ， 测试计量技术及仪器， 2001， 硕士

【摘要】 接触式电容压力传感器不仅具有一般电容式传感器灵敏度高等优点，而且在其测量的压力范围内，传感器的输出电容与载荷呈分段线性关系，因此与其它需要改进电极结构和测量电路进行非线性补偿的电容式压力传感器来讲，具有结构简单、性能优越、抗过载能力和抗干扰能力强等优点。由于微传感器的测量分辨输出电容很小，远远小于皮法，如何提高小电容的测量电路的灵敏度和改善全量程测试中的非线性直接影响传感器的性能。MEMS(Micro Elcetro-Mechanical System)技术和IC(Integrated Circuit)以及计算机技术的发展，使得半导体压力传感器与其测量电路的集成和非线性补偿电路的集成成为可能，这是未来传感器发展的趋势。传感器的微型化发展趋势和IT技术的高度发展，以及某些特殊应用的特殊要求，对传感器的测量精度、测量环境和测量方式提出了更高的要求，而恶劣封闭的测量环境往往要求微型传感器系统具有远程测量的功能。MEMS技术、IC技术和IT(Information Technology)技术的发展为传感器测量系统实现无线化提供了坚实的基础。目前有关MEMS集成系统、无线MEMS技术和基于微传感器的无线MEMS系统在IEEE的各种刊物上已经有一些相关的报道，但相关的产业化研究报道很少。用接触式电容压力传感器为调制信号源的无线传输系统国、内外未见相关报道。本文的主要研究工作如下： 1．以接触式电容压力传感器为基础，通过对它的非线性力学模型的分析，提出了由集成电路构成的考虑力学模型特点的具有非线性补偿的电容测量电路和模型以及由接触式电容压力传感器构成的无线通讯系统。 2．根据接触式电容压力传感器具有两个分段线性测量区域的特点，以模拟乘法器为核心部件，利用它的鉴相特性，设计了高线性度(线性度约为3.42％)和高灵敏度(28mV/pF)的电容测量电路，解决了电容式传感器的小电容测量问题，提出了可实现接触式传感器全量程准线性的测量。 3．为便于实现传感器与测量电路的集成，基于开关电容电路的原理设计出了频率输出的CMOS电容信号处理电路。 4．以MEMS工艺和CMOS电路为基础，对传感器的无线测量电路进行了解析研究，设计了以CMOS吉尔伯特单元为核心的移相键控调制解调无线通讯电路。 5．通过仿真实验和电路实验，验证了电容式压力传感器小电容信号测试和无线测量系统的可行性。更多还原

【Abstract】 The touch mode capacitive pressure sensor not only has high sensitivity and many merits that other forms of capacitive pressure sensors have, but also has good segment linearity between the load pressure and the output capacitor within the range of operation. Compared with other capacitive pressure sensors whose structure or measurement circuit has to be changed in order to improve their linearity, touch mode capacitive sensor has the merits of simple structure, excellent performance and strong ability of overload and anti-interfering. How to improve the sensitivity of the measurement circuit and linearity of the sensor within its full-scale will influence the performance of the sensor in respect that the discriminable output capacitance of microsensors is much less than IFF. The developing of the technology of MEMS (Micro Elcetro-Mechanical System) and 1C (Integrated Circuit) and computer make it possible to integrate the semiconductor pressure sensor with its measurement circuit and the non-linearity compensation circuit, which will be the tendency of the developing of sensors. The tendency of the minisize of sensors and the development of information technology, at the same time, some application in special circumstance needs microsensors that have the ability of remote measurement, especially under the coarse and hermetic circumstance. The developing of MEMS, 1C and IT establish the base of wireless measurement of sensors. Nowadays, there are some reports on MEMS integrated systems, wireless MEMS technology and MEMS wireless systems based on microsensors in the references of IEEE, but there are a few relative reports on the industrialization of them. Reports on the wireless measurement systems using the touch mode capacitive pressure sensors as their signal sources are not presented all over the world including China yet. The research in this thesis is contented as follows:1. The model of touch mode capacitive pressure sensor has been analyzed and a kind of small capacitance measurement circuit with non-linearity compensation constructed by integrate circuits and the wireless communication system of the capacitive sensor are presented.2.Based on the characteristic of segment linearity of the sensor, the design of the measurement circuit constructed by integrate circuit takes the multiplier (MCI596) as its core taking use of its phase detect characteristic. The circuit has good linearity (non-linearity 3.42%) and high sensitivity (28mV/pF) and the small capacitance is measured. The measurement of the segment linearity of the sensor can be achieved through changing the structure of the circuit3.To integrate the sensor with its measurement circuit, the CMOS capacitance signal processing circuit is designed based on the theory of capacitor switch circuit.4.The wireless measurement circuit of the sensor is analyzed and researched based on the process of MEMS and CMOS circuit and the phase shift keying modulation and demodulation circuits are designed with the core of CMOS Gilbert unit.5. The feasibility of the signal processing and modulation and demodulation circuits is verified through the simulation of the circuit and experiments.更多还原