A 190-GHz High-Gain, 3-dBm OP1dB Low DC-Power Amplifier in 250-nm InP HBT

We report a 190-GHz amplifier designed into a 250-nm InP HBT technology. The four-stage amplifier at 76-mW dc power Pdc demonstrates 25-dB S
₂₁
gain and 24-GHz 3-dB bandwidth. At 190-GHz operation, the saturated output power P
_sat
is 9.7-mW with 9.4% PAE and 16.4-dB large-signal gain. The 1-dB gain compression power OP1dB is 3-dBm. Biased at 97-mW P
_dc
using higher HBT collector voltage, the amplifier demonstrates 22.4-dB S
₂₁
gain and 26-GHz 3-dB bandwidth. At 190-GHz operation, P
_sat
increases to 12.7-mW with 9.5% PAE and 19.2-dB large-signal gain. The OP1dB is also 3 dBm. Very similar OP1dB, Psat, and PAE large-signal characteristics were observed at 185and 195-GHz operation. This letter represents world-class efficiency and record 1.59-W/mm power density for an InP HBT amplifier operating at G-band, and it competes equally well with the state-of-the-art results demonstrated in advanced InP HEMT, SiGe HBT, and CMOS technologies.