如何提高CMOS LNA的IIP3？哪些因素限制了IIP3，P1DB指标？

dolphin75 · 发表于 2009-7-9 18:16:56

15dBm的IIP3,要求高了些。你的NF多大？

tideblue · 发表于 2009-7-9 18:46:27

some state-of-the-art idea:
1 gm3 in linear region has opposite polarity compared to saturated region, this can also be used to cancel 3rd order harmonic
2 in deep sub-micro(<65nm) , harmonic term in gm(e.g g12,g41) become the main source of 3rd order non linearity, find a way to reduce them also improve IIP3

原帖由 Rainleo 于 2008-7-17 07:45 发表

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众所周知，IIP3是由于MOS管IV的非线性引起的。我们知道MOS管的gm不是跟vgs简单的正比关系，而是存在非线性特性。如果用Taylor级数展开，gm可以表示为：gm=gm0+gm1*vov+gm2*vov^2+gm3*vov^3+gm4*vov^4+...
其中，vov ...