A 150–175-GHz 30-dB S 21 Power Amplifier With 125-mW P out and 16.2% PAE Using InP HBT.

We report a five-gain-stage 150–175-GHz solid-state power amplifier (PA, SSPA) monolithic microwave integrated circuit (MMIC) having modest 20–21-dBm output power $P_{\mathrm {out}}$ , high gain, and high power-added efficiency (PAE). The transistor technology is 250-nm InP HBT. The $S_{21}$ gain is 31.4 ± 1.2 dB from 100 to 178 GHz. The 3-dB $S_{21}$ bandwidth is between 96 and 181 GHz. Typical return loss values for $\vert S_{11}\vert $ and $\vert S_{22}\vert $ exceed 8.5 and 10 dB, respectively. The dc power is 0.72 W. Across 150–175 GHz, the saturated output power $P_{\mathrm {sat}}$ is 106–126 mW with 16–18-dB gain and 12.5%–16.2% PAE—peak values for $P_{\mathrm {out}}$ , gain, and PAE are at 170-GHz operation. The 1-dB gain compression $P_{\mathrm {out}}$ (OP $_{\mathrm {1\,dB}}$) is 30–60 mW. Across the $D$ -band (110–170 GHz), $P_{\mathrm {sat}}$ is 82–126 mW with 9.1%–16.2% PAE. This work establishes a 1.62– $1.89\times $ increase to PAE over 150–175 GHz operation at the output power and gain levels cited. It is also the highest RF output power demonstrated across the full 110–170-GHz WR6.5 waveguide band. [ABSTRACT FROM AUTHOR]