ABSTRACT
Pseudomorphic pulse-doped (PPD) MESFETs with a Si-doped GalnAs active layer have been successfully developed for low noise application. The devices with 0.35μm gate-length exhibited as good linearity as pulse-doped MESFETs with a Si-doped GaAs active layer. The maximum transconductance (gmmax) and the transconductance (gm) at low drain current (≃0.2 Idss) were 380mS/mm and 250mS/mm, respectively. These values are 10~20% higher than those of the pulse-doped MESFETs. The minimum noise figure (Fmin) of the PPD-MESFETs is 0.74dB at 12GHz for 0.35μm devices, which is 0.1dB lower than that of the pulse-doped MESFETs.
