300 GHz broadband power amplifier with 508 GHz gain-bandwidth product and 8 dBm output power

This paper presents a broadband H-band (220 -325 GHz) power amplifier in a 35 nm InGaAs-based metamorphic high electron mobility transistor technology. The amplifier is realized as a submillimeter-wave monolithic integrated circuit (S-MMIC) and is designed to drive a high power amplifier in a multi-gigabit communication system. The five-stage amplifier S-MMIC based on common-source gain cells was realized and measured on-wafer with a maximum gain of 23 dB at 285 GHz. The lower and higher cutoff frequency is 278 and 335 GHz, respectively, with a gain variation of around 4 dB. The amplifier has four parallel transistors in the last two stages and provides a saturated output power of 8 dBm at 300 GHz. A gain-bandwidth product (GBW) of 508 GHz could be achieved.