Output conductance frequency dispersion and low-frequency noise in HEMTs and MESFETs

摘要

It is reported that the high level of low-frequency noise observed in MESFETs and HEMTs in the saturation regime usually scales with the device output conductance frequency dispersion (in MESFETs) or with parallel conduction through the GaAlAs (in HEMTs). It does not seem to be directly related to output resistance frequency dispersion. The fundamental cause of output resistance dispersion in HEMTs is still unknown. Thermal feedback effects, low-frequency variations of series resistances, and trap-related effects are possibilities that require investigation.