摘要
Much research work and many reviews about the noise in FET have been reported. In general, the noise of the FET can be divided into two parts for discussion. One of them is the current noise, whose contribution to the total noise voltage is relevant to the impedance at the input terminal; the other is the voltage noise which is independent of the impedance. The former is the main noise source for low-noise high impedance preamplifier, and according to van Der Ziel, it includes two noise sources: the shot noise due to gate current and the gate-induced noise. The shot noise is independent of frequency, while the gate-induced noise is proportional to it. The
