Effect of collector bias current on the linearity of common-emitter BJT amplifiers  

作　　者：李琨 滕建辅 轩秀巍 

机构地区：[1]School of Electronic and Information Engineering,Tianjin University of Technology [2]School of Electronic and Information Engineering,Tianjin University

出　　处：《Journal of Semiconductors》2010年第12期75-79,共5页半导体学报（英文版）

基　　金：Project supported by the Tianjin Natural Science Foundation,China(No.09JCYBJC00700)

摘　　要：Using a Volterra series, an explicit formula is derived for the connection between input 3rd-order intercept point and collector bias current （IcQ） in a common-emitter bipolar junction transistor amplifier. The analysis indicates that the larger/CQ is, the more linear the amplifier is. Furthermore, this has been verified by experiment. This study also integrates a method called dynamic bias current for expanding the dynamic range of an LNA （low noise amplifier） as an application of the analysis result obtained above. IMR3 （3rd-order intermodulation rate） is applied to evaluate the LNA＇s performance with and without adopting this method in this study.Using a Volterra series, an explicit formula is derived for the connection between input 3rd-order intercept point and collector bias current （IcQ） in a common-emitter bipolar junction transistor amplifier. The analysis indicates that the larger/CQ is, the more linear the amplifier is. Furthermore, this has been verified by experiment. This study also integrates a method called dynamic bias current for expanding the dynamic range of an LNA （low noise amplifier） as an application of the analysis result obtained above. IMR3 （3rd-order intermodulation rate） is applied to evaluate the LNA＇s performance with and without adopting this method in this study.

关 键 词：IIP3 collector bias current BJT dynamic bias current 

分 类 号：TN32[电子电信—物理电子学]