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：Contemporary radio observatories use arrays of LNAs to develop higher-resolution maps of radio sources a lot of light-weight-years absent.He even hits over a transmit/obtain