A Compact 140-GHz, 150-mW High-Gain Power Amplifier MMIC in 250-nm InP HBT

We report here a compact 140-GHz, 150-mW highgain solid-state power amplifier (SSPA) monolithic microwave integrated circuit (MMIC) demonstrated in a 250-nm InP HBT technology. It utilizes five-gain stages and two-way on-chip power combining. The amplifier measures 29.5-dB mid-band S21 gain and over 125-mW output power across 115-150-GHz operation. The peak 153-mW output power was measured at 140 GHz using only 2.7-mW RF input power-the associated large-signal gain is 17.5 dB with 9.8% power added efficiency (PAE). The 140-GHz OP1 dB 1-dB gain compression power is 106 mW with 7.0% PAE. The dc power dissipation is 1.54 W and its size is only 0.75 mm2. The 3-dB S21 gain roll-off is between 112 and 147 GHz. The 115-150-GHz output power variation at 0-dBm input drive is only +/- 0.5 dB. The peak PAE varies between 8.2% and 10.5%. This D-band result improves upon by 2.3x at 140 GHz the state-of-theart peak RF power previously demonstrated by SSPA MMICs.