噪声系数通常用于衡量一个电路和或者系统内部噪声大小，它通常用于比较不同电路或者系统噪声性能的好坏。噪声系数的定义如下： This short article requirements extra citations for verification. Remember to support improve this informative article by including citations to reliable sources. Unsourced substance might be challenged and eradicated. LNAs are meant to reduce that added noise, by pic... https://yurii788rlf3.wikijournalist.com/user