AlGaAs/InGaAs/AlGaAs double-side planar-doped (DSPD) pseudomorphic MODFET's of 0.3-mu-m gate length with both excellent dc and RF performance have been fabricated. A maximum unilateral gain cutoff frequency of f(C) = 170 GHz and a maximum current gain cutoff frequency of f(T) = 60 GHz have been achieved. The devices exhibit a maximum transconductance of 500 mS/mm and an extremely high current density of 1 A/mm. These are the highest frequencies report so far for MODFET devices being capable of driving 1-A/mm current density. This current density is the highest ever reported with this type of layer structure.