The estimation of HF power pulse effect on FET´s noise figure

A simple method is developed for estimation of HF power pulse effect on FET noise figure under the operating conditions. The method is based on measurement of the evolution of drain current and FET gain. The group of 8 transistors has been measured and analyzed. The estimations show that the noise figure of some FET is rising more than twice under the exposition of HF power pulse of allowable amplitude. It has been shown that the analyzed transistors fall into three groups: (1) transistors which have low sensitivity to input HF pulse power for all allowable amplitudes; (2) transistors which have low sensitivity to input HF pulse power for low amplitude; (3) transistors which are sensitive to input HF pulse power. It is very interesting that the gain of the first group of transistors has also low sensitivity to input HF pulse power.