A 220-GHz Power Amplifier With 60-mW Pout and 23.5% PAE in 130-nm InP HBT

We report a two gain-stage 220-GHz solid-state power amplifier (SSPA) monolithic integrated circuit (MMIC) having high output power (
$P_{\text {out}}$
) and record power-added efficiency (PAE) exceeding 20% above 200-GHz operation. The transistor technology is 130-nm InP HBT. The
$S_{21}$
mid-band gain is 13.9-dB. Typical return loss values for
$\vert S_{11}\vert $
and
$\vert S_{22}\vert $
exceed 6.3- and 12.7-dB, respectively. The dc power dissipation is 183-mW (
$P_{\text {dc}}$
). From 217.5- to 225-GHz, the saturated output power
$P_{\text {sat}}$
is 57–62-mW (1.78–1.93 W/mm RF power density) with 6.1–6.5 dB gain and 20%–23.8% PAE–peak values for
$P_{\text {out}}$
, gain, and PAE are at 220-GHz operation. The 1-dB gain compression
$P_{\text {out}}$
(OP
$_{1\,\text {dB}}$
) at 220-GHz is 31.6-mW with 15.9% PAE. The power amplifier is very compact, 0.192-mm2 in size. This work represents the first solid-state power amplifier operating above 200-GHz having PAE greater than 20%. Compared to the previous state-of-the-art, PAE has been increased by 1.36 times; however, when compared to 200-GHz PAs with similar output power, state-of-the-art PAE has instead been increased by 2.3 times.