Voltage gain enhancement by conductance cancellation in GaAs MESFET opamps

GaAs MESFET analog circuits have relatively low gain. To enhance the gain, positive feedback can be used to allow output conductance cancellation between the drive and active load transistors. This decreases the effective output conductance and increases the voltage gain of the amplifying stage without the need for cascode stages. A GaAs MESFET operational amplifier using this scheme, implemented in a 1-/spl mu/m non-self-aligned GaAs technology, achieves a DC gain of 60 dB and a bandwidth of 840 MHz.<>