A 75-305-GHz Power Amplifier MMIC with 10-14.9-dBm Pout in a 35-nm InGaAs mHEMT Technology

The demonstration of a 75-305-GHz power amplifier (PA) monolithic microwave integrated circuit (MMIC) is presented in this letter. The PA is based on an eight-cell traveling-wave unit amplifier (UA). Each cell contains an RF cascode with two two-finger transistors with a gate width of 20 mm each. In the output stage, a balanced configuration combines two UAs with Lange couplers. In front, a third UA is used as a driver amplifier. The PA MMIC is fabricated in a 35-nm gate-length metamorphic high-electron-mobility transistor technology. From 75 to 305 GHz, the PA yields a minimum output power of 10 dBm with an average value of 12.8 dBm. At 200 GHz, a peak output power and PAE of 14.9 dBm and 6.6% is achieved, respectively. To the best of the authors' knowledge, this is the first PA MMIC with an octave-bandwidth that provides an output power of 10 dBm at 300 GHz.