Operational Transconductance Amplifier Circuit Using GaAs MESFETs

Abstract

This paper describes an operational transconductance amplifier circuit (OTA)using n-channel depletion GaAs (gallium arsenide) MESFET devices. The circuit consists of GaAs current mirror and a simple transconductor circuit. It will be shown that the way to adjust the circuit’s transconductance gain is convenience by only control the differential tail pair bias current. Designed to work in current mode using GaAsMESFETs, so circuit can operate in very high frequency band. The results of using PSPICE analogue simulation program analysis show that the properties of the circuitare in close agreement with the theoretical prediction.