Comparison of GaAs MESFET noise figures

A method of comparing GaAs MESFET noise figures for a variety of material and process technologies is presented. The method which involves plotting the noise measure as a function of gate length for devices having the lowest noise value gives a figure of merit graph against which other devices may be compared. The available data is clustered around three frequencies: 8, 12, and 18-20 GHz, and it is shown that these data extrapolate to a finite noise figure for zero gate length. The gate length is shown to be a significant factor in determining performance. A comparison of MODFET's (modulation-doped MESFET's) and MESFET's indicates that the noise in two-dimensional electron devices (MODFET's) is substantially lower than the noise in three-dimensional electron gas devices (MESFET's).