Nonlinear GaAs MESFET modeling using pulsed gate measurements

The effects of traps in GaAs MESFETS are studied using a pulsed gate measurement system. The devices are pulsed into the active region for 1 mu s and are held in the cutoff region for the rest of a 1-ms period. While the devices are on, the drain current is sampled and a series of pulsed gate I-V curves are obtained and compared to conventional static I-V curves. The static and pulsed gate curves were used in a nonlinear time-domain analysis model to predict harmonic content. The results showed that models which used the pulsed gate I-V curves to represent the nonlinear drain current yielded better predictions of harmonic distortion than models which used conventional I-V curves.<>