基于电流模式的高频弱信号精密整流电路  

Current mode based precision rectifier circuit for high-frequency weak signal

作　　者：刘士兴[1] 冯婷婷[1] 陈雨露[1] 易茂祥[1] LIU Shixing;FENG Tingting;CHEN Yulu;YI Maoxiang(School of Electronic Science and Applied Physics,Hefei University of Technology,Hefei 230009,China)

机构地区：[1]合肥工业大学电子科学与应用物理学院,安徽合肥230009

出　　处：《现代电子技术》2016年第14期139-142,146,共5页Modern Electronics Technique

基　　金：国家自然科学面上基金项目资助(61371025)

摘　　要：精密整流电路广泛应用于交流信号测量和模拟信号处理系统,是微弱信号采样和测量电路的重要组成部分。阐述了通用精密整流电路整流特性,详细分析信号过零时因整流二极管截止而产生的误差,提出基于第二代电流传输器(CCⅡ)的高频弱信号精密整流电路,采用电流运算放大器AD844实现CCⅡ模型使电路工作在电流模式。仿真分析结果表明,该电路能够精确整流最小幅值10 m V,上限截止频率高达10 MHz的输入信号,有效避免了常用电压模式整流电路对频率的限制及信号过零附近的失真,提高了弱信号整流精度。The precision rectifier circuit is widely used in AC signal measurement and analog signal processing system,and is an important component of the weak signal sampling and measuring circuit. In this paper,the rectification characteristicof the general precision rectifier circuit is explained,and the error generated by the rectifier diode cutoff while signal is crossingzero is analyzed in detail. The precision rectifier circuit for high?frequency weak signal,based on CCⅡ(the second generationcurrent conveyor),is put forward. The current operational amplifier AD844 is used to realize the CCⅡ model and make the cir?cuit work in current mode. The simulation results show that the circuit can precisely rectify the input signal,whose minimum am?plitude is 10 mV and upper cut?off frequency can reach up to 10 MHz. The circuit can effectively avoid the frequency restrictionof the common voltage mode rectifier circuit and signal distortion near the zero?crossing,and improve the rectification accuracyof the weak signal.

关 键 词：精密整流电路 第二代电流传输器 高频弱信号 电流模式 

分 类 号：TN70-34[电子电信—电路与系统]