Improved negative feedback technique to reduce drain conductance of GaAs MESFETs for precision analogue ICs

An improved negative feedback technique to reduce the absolute magnitude of the frequency-dependent drain conductance inherent in GaAs MESFETs has been demonstrated for low-threshold (less than −1 V) devices. The new dual-threshold arrangement guarantees that the primary device of the self-bootstrapping pair operates at the current saturation region without relying on the existence of early saturation. A factor of 11 reduction in the drain conductance was realised. A simple inverter amplifier of identical composite driver and load has demonstrated 21 dB improvement in voltage gain over that using single FETs.