Field-effect transitor differential amplifier

Abstract

The feasibility of using field-effect transistors in wide-band differential amplifier applications has been investigated. An analysis of bipolar transistor differential amplifiers is included which demonstrates the problem of thermal drift and low input impedance present in all low level transistor amplifiers. An investigation of a field-effect transistor shows that such a device possesses the properties of zero thermal drift at a particular bias point, extremely high input impedance, good radiation resistance, low noise, and a high power gain. It is therefore postulated that employing FET\u27s in a differential amplifier will result in a circuit having very high input impedance and low thermal drift