一款JFET低噪声前置放大器的设计  

Design of JFET Low Noise Preamplifier

作　　者：张晓飞[1] 董浩斌[1] 鲁永康[1] 吴鹏[1] 

机构地区：[1]中国地质大学(武汉)机械与电子信息学院,湖北武汉430074

出　　处：《电声技术》2009年第11期34-36,共3页Audio Engineering

摘　　要：在对级联网络及结型场效应管的噪声分析基础上,采用结型场效应管等分立元件设计了一款低噪声前置放大器实用电路。并对其幅频特性、输入阻抗和等效输入噪声进行了测量,结果表明其输入阻抗高达71MΩ,等效输入噪声电压为0.7nV/((Hz)^(1/2)),是一种适合于较高内阻传感器的较理想的低噪声前置放大器电路。Based on the noise analysis of the the series-wound amplifiers and the JFET, an applied circuit of low-noise preamplifier is designed using JFET and discrete components. The amplitude-frequency characteristics, input impedance and the equivalent input noise voltage are tested. The result indicates that the circuit＇s input impedance is 71 MΩ and the equivalent input noise voltage is 0.7 nV/√Hz. It is an ideal circuh of low noise preamplifier for the sensors with high internal resistance.

关 键 词：结型场效应管 低噪声 前置放大器 较高内阻传感器 

分 类 号：TN722.3[电子电信—电路与系统]