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： Radio telescopes integrate LNAs to capture weak electromagnetic signals from celestial bodies. These specialized amplifiers work with noise temperatures under 15 Kelvin to detect cosmic signals at ability levels of -one hundred thirty dBm. Any resistance while in the ... https://fredericj555icw9.gigswiki.com/user