作者：沈毅鸿, 张元良

作者单位：大连理工大学机械工程学院, 辽宁 大连 116023

关键词：阻抗谱测量;幅相检测;最小二乘法;自适应匹配

摘要：

为满足工程应用中的阻抗谱测量需求，设计一种高精度的阻抗谱自动测量系统。该系统采用DDS及压控恒流源产生可调激励电流信号，通过模拟开关自适应匹配采样电阻及移相电容以提升测量精度，通过在测量前选通校准阻抗进行最小二乘法校准，使用仪表放大器及幅相检测芯片AD8302获得响应信号，最终由微控制器计算获得待测阻抗。测试表明：系统可在1 kHz~10 MHz的频率范围内正常工作，测量得到的复阻抗值及阻抗谱误差较小。

Design of an automatic impedance spectrum measuring system based on AD8302

SHEN Yihong, ZHANG Yuanliang

School of Mechanical Engineering, Dalian University of Technology, Dalian 116023, China

Abstract: This paper's objective was to design an automatic measuring system for the impedance spectrum in order to meet the requirements of engineering application, which included the use of DDS and VCCS to generate an adjustable drive current, choosing the most suitable sampling resistor and phase-shifting capacitor adaptively by analog multi-channel switch to achieve higher accuracy, and selecting the calibration impedance for least-square calibration prior to measuring, then acquiring response signals through instrumentation amplifier and the gain and phase detector AD8302. Finally, the microcontroller calculated the impedance under tested. The above tests had shown that the system can obtain accurate impedance values and spectra within a wide frequency range of 1 kHz-10 MHz.

Keywords: impedance spectrum measurement;gain and phase detection;LSE;adaptive matching

2018, 44(9): 90-95  收稿日期: 2018-04-10;收到修改稿日期: 2018-05-22

基金项目: 

作者简介: 沈毅鸿(1994-),男,湖南岳阳市人,硕士研究生,专业方向为智能仪器仪表设计

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