Noise behavior of GaAs Schottky-Barrier field-effect transistors in the microwave region

Recently it has been shown that GaAs FET´s with a Schottky-barrier gate are very promising devices for microwave applications. Transistors with a maximum frequency of oscillation of 30 GHz have been reported. The noise behavior of such devices has been investigated theoretically and experimentally. Compared to silicon devices, an additional noise source has to be taken into account in the GaAs FET--the intervalley scattering noise. This kind of noise occurs if carriers are scattered from the central valley to a satellite valley where the mobility is considerably reduced. This noise is very similar to the well-known generation-recombination noise.