THE COMPRESSIVE NATURE OF OPTICAL-DETECTION IN GAAS-MESFETS AND POSSIBLE APPLICATION AS AN RF LOGARITHMIC AMPLIFIER

The photodetection mechanisms in GaAs MESFETs have been investigated b y several researchers. Recently the authors have published an in-depth study of the MESFET as an optical detector under constant illuminatio n involving both experimental and theoretical modelling. In this paper we discuss the compressive nature of that photodetection process. Exp erimental results involving constant illumination, modulated light and pulsed illumination verify the theoretical conclusions. Finally we pr esent a suggested structure of an RF logarithmic amplifier based on th e above phenomenon.