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