CMOS低噪声放大器的噪声系数优化研究

由于CMOS晶体管的特征尺寸急速的缩放,CMOS晶体管的参数不断改进,使得最新CMOS晶体管获得的噪声系数足够低到足以应用到无线电天文学,因此,在本研究课题中选用CMOS晶体管。目前的低噪声放大器的最小噪声系数是在室温环境下,通过宽带CMOS低噪声放大器的功率匹配来获得。在本研究课题中,CMOS低噪声放大器以共源共栅极结构为基本拓扑结构,主要研究LNA的几种常用的噪声系数优化方法。通过建立小信号模型,对LNA的噪声系数进行分析,得出相应的表达式。

Study on Noise Figure Optimizations of CMOS Low Noise Amplifier

Owing to the rapid scaling of its feature sizes, the technical parameters of CMOS transistor are constantly improved, thus making the latest CMOS transistor achieve the noise figures low enough to be used in the radio astronomy. So the CMOS transistor is chosen for the present research project. The lowest noise figure of the present LNA is known to be achieved by power-matched wideband CMOS LNA at room temperature. This project focuses on CMOS LNA based on the cascode topology, places emphasis on the research of several common optimizations of noise figure. The noise figure in LNA is discussed, and its expression is derived by building the small-signal model.