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Design >> RF Design >> about the noise analysis of LNA
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Message started by calven on Oct 17^th, 2006, 8:55am

Title: about the noise analysis of LNA
Post by calven on Oct 17^th, 2006, 8:55am

dear all,
i am learning the design of LNA using the book written by thomas lee.when analyzing the noise parameters of CMOS LNA,it ignores the flicker noise. why can we ignore the flicker noise?because it dominates in the low frequency?
thanks!

Title: Re: about the noise analysis of LNA
Post by ACWWong on Oct 17^th, 2006, 10:21am

correct, normally the flicker noise of the active LNA devices doesn't contribute at the frequency of interest.... so excluded in hand equation analysis.

but sometimes you need to be careful of low frequency flicker noise in bias circuits for things like LNAs, sometimes this low frequency noise can be modulated up (by blockers for example) to RF to cause you problems in certain conditions...