THE EFFECT OF PARASITIC COMPONENTS OF GAAS-FETS ON HIGH-FREQUENCY GAIN

Abstract

Parasitic component effects on the gain of GaAs FETs are described. Numerical simulation shows that the frequency range of the unstable region (K < 1) of an FET decreases as gate resistance, drain resistance, or source inductance increases, and as source resistance decreases. The increase of gate or drain resistance does not affect MSG but does reduce MAG. The increase of source inductance or resistance reduces MSG and MAG. The Mag degradation is due to the decrease of \y21/y12\ for the source resistance and the increase of K for the other parasitics. These findings should be helpful in the design and analysis of microwave GaAs FETS.