The gate current noise of junction field effect transistors

Abstract

A circuit is described to measure the noise in the gate current of field effect transistors. A sensitivity corresponding to a shot noise of a current 3*10-13 A was achieved. In most devices the equivalent input current noise source spectrum was found to be white and due to the gate current short noise. In some devices excess low frequency noise components were found in the voltage and current equivalent noise sources. These have been investigated and related to specific noise sources and current leakage mechanisms.