低噪声前置放大器有源器件的选择  

The choice of active device about lower-noise preamplifier

作　　者：郭玉[1] 赵顺平[2] 

机构地区：[1]安庆师范学院物理与电气工程学院,安徽安庆246011 [2]安庆师范学院化学与环境科学学院,安徽安庆246011

出　　处：《电测与仪表》2007年第6期62-64,共3页Electrical Measurement & Instrumentation

摘　　要：根据噪声理论及等效噪声模型,本文推导了前置放大器的噪声特性指标。为了达到最佳噪声匹配,分析比较了双极型晶体管(BJT)、集成运放及场效应管(FET)的内阻、噪声特性及三种不同耦合方式的特点,从而总结出对于低内阻信号源较理想的前置放大器的有源器件是单级或多级并联双极型晶体管。According to noise theory and equivalent noise model, deduced noise characteristic indexes. In order to get the optimal noisy matching, analyzed and compared inside resistance and noise characteristics of bipolar junction transistor （BJT）.integrated operation amplifier and iunction field-effect transistor （FET）and the characteristics of three coupled modes. Consequently educed single or Multi-Parallel-transistors is a ideal active device of the preamplifier for the signal source with low resistance.

关 键 词：等效噪声模型 噪声系数 噪声匹配 耦合方式 

分 类 号：TN72[电子电信—电路与系统]