新型叉指电容设计建模与实验研究  

Designing Modeling and Experimental Research on Novel Interdigital Capacitor

作　　者：唐忠林 杨建华[2] TANG Zhong-lin;YANG Jian-hua(School of Aeronautical Engineering,Shaanxi Polytechnic Institute,Xianyang 712000,China;School of Automation,Northwest Polytechnical University,Xi’an 710072,China)

机构地区：[1]陕西工业职业技术学院航空工程学院,陕西咸阳712000 [2]西北工业大学自动化学院,陕西西安710072

出　　处：《仪表技术与传感器》2021年第10期16-22,共7页Instrument Technique and Sensor

基　　金：国家重点研发计划(2017YFC0211500);陕西省教育厅2020年服务地方专项科学研究计划(20JC002);陕西工业职业技术学院2019年自然科学类重点项目(ZK19-02)。

摘　　要：文中设计一种具有交扣叉指结构和等电位隔离电极的新型叉指电容,建立了新型叉指电容的表面电容通用解析模型,并进行了实验验证。结果表明:表面电容解析模型的理论计算值与实际测量总电容值之间存在高度的线性相关性,线性拟合的最大相对偏差为0.34%;新型叉指电容在1 kHz~1 MHz频率范围内实测电容值的相对变化量稳定地小于基本结构叉指电容,最大变化量约为后者的91%;电容表面覆膜时的有效感知厚度随电极占空比的增加而增加,达到增速拐点之后敏感度随膜厚增加而显著减小。新型叉指电容的解析模型简洁、准确,设计制造方便。A new type of interdigital capacitor(IDC)with interlocked interdigital fingers and equipotential isolating electrodes was designed.The general analytical model of the IDC’s surface capacitance was constructed.Experiments were conducted to verify the results.The results show that there is a high linear correlation between the theoretical calculated value of the analytical model of surface capacitance and the actual measured total capacitance, linear fitting has a maximum error of 0.34%.In the frequency range from 1 kHz to 1 MHz, capacitance increment of the new IDC is steadily less than the basic IDC,with a maximum value of about 91% of the latter.The effective sensitive height of the IDC increases according to the electrode duty ratio.After reaching the inflection point of growth rate, the sensitivity decreases significantly with the increase of film thickness.The analytical model of the new IDC is simple, accurate and convenient to design and manufacture.

关 键 词：传感器 叉指电容 电场分布 等电位隔离 保角变换 许瓦兹-克里斯多夫变换 

分 类 号：TP212[自动化与计算机技术—检测技术与自动化装置]