A 6–10 mW Power Amplifier at 290–307.5 GHz in 250 nm InP HBT

A 290-307.5 GHz solid-state power-amplifier MMIC is presented demonstrating 6-10 mW P
_out
for P
_in
<; 0.8 mW. P
_DC
is 848 mW. This represents 10-12 dB of large-signal gain across 18 GHz of high-power bandwidth. This 3-stage amplifier has peak 23.5 dB S
₂₁
gain at 299 GHz, a 1 dB bandwidth from 292-303 GHz, and a 3 dB bandwidth from 285-306 GHz. A power-cascode cell topology is used for the PA unit cell and 2:1 Wilkinson power combining of these cells (32 um HBT output periphery) achieves the RF powers claimed. The insertion loss demonstrated by the combiner is 0.45-0.5 dB from 255-330 GHz-this improves upon state-of-the-art for on-wafer 2:1 combining at these frequencies by 0.3-0.7 dB. This work represents the first demonstration of a 300 GHz power cascode cell topology with output power and output power density (W/mm) competitive with state-of-the-art PAs with 10 mW P
_out
.