Two-Stage 94 GHz drive Amplifiers Using 0.1-μm Metamorphic HEMT Technology

In this paper, millimeter-wave 94 GHz drive amplifiers based on metamorphic high electron mobility transistors (MHEMTs) were designed and fabricated. The fabricated 100 nm gate length MHEMT devices exhibit DC characteristics with a drain current density of 690 mA/mm and an extrinsic transconductance of 770mS/mm. The current gain cutoff frequency (f
_T
) and the maximum oscillation frequency (f
_max
) are 185 GHz and 230 GHz, respectively. The matching circuit of amplifier was designed using CPW (coplanar wave-guide) transmission line. The fabricated amplifier shows a good S
₂₁
gain of 7.79 dB, an input return loss (S
₁₁
) of -16.5 dB and an output return loss (S
₂₂
) of-15.9 dB.