A coplanar 148 GHz cascode amplifier MMIC using 0.15 µm GaAs PHEMTs

A two-stage D-band amplifier MMIC with 12 dB gain at 148 GHz has been developed, using a 0.15 mu m AlGaAs/InGaAs/GaAs PHEMT technology. The amplifier employs cascode HEMT devices with 2 x 30 mu m gate periphery, having a maximum oscillation frequency f(Ind max) of 180 GHz. On-wafer vector measurements up to 200 GHz were performed using active probes based on nonlinear transmission fines. The circuit features coplanar technology for compact size and low cost. The overall chip-size is 1 x 1.5 mm2.