A link between noise parameters and light exposure in GaAs pHEMT’s

This work presents an experimental investigation and relevant discussion of the link existing between noise parameters and light exposure of GaAs pseudomorphic HEMT’s at microwave frequencies. A 100 [mi]m gate width AlGaAs/InGaAs/GaAs heterostructure device has been illuminated with CW visible laser light (650 nm) and a systematic analysis has been performed by examining the device behavior under controlled bias current conditions. Significant effects have been brought to evidence in the 2–26 GHz noise parameters Fmin, Copt and Rn measured in the different conditions. A clear correlation has been found between the level of degradation of the noise parameter behavior and the light exposure.