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： ）在通信系统中扮演着至关重要的角色。它是接收链路的第一级，其主要任务是将微弱的射频信号放大，同时尽可能地保持信号质量，降 Without the op amp, the obtain of that construction is about 85 dB alone which has a -three dB all over 250 kHz. I simply cannot confirm that it go... https://pindiodeswitch48024.thekatyblog.com/32918834/pin-diode-switch-no-further-a-mystery