关于noise figure

nm2012

使用noise分析得出来的noise figure和用sp分析得出来的NF有什么区别么，仿真出来感觉不太一样啊，用sp仿真出来的要小一些这是为什么，求助，thx

challengersy

同问，用PSS+PNOISE仿真的LNA的NF和SP仿真的LNA的NF差的很大

richard1993

If you use SP analysis, it gives you the small signal NF, namely, the DC biasing points are fixed. However, if you use PSS or HB, it is large signal analysis, DC biasing points are varying with input signals. The two corresponding results are obviously different then.
The differnet results between SP analysis and nosie analysis is due to your set-up, if your set-up is correct, you should obtain similar results