A 220-GHz Power Amplifier With 60-mW P out 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 ( <tex-math notation="LaTeX">Pₒᵤₜ </tex-math> ) and record power-added efficiency (PAE) exceeding 20% above 200-GHz operation. The transistor technology is 130-nm InP HBT. The <tex-math notation="LaTeX">S₂₁ </tex-math> mid-band gain is 13.9-dB. Typical return loss values for <tex-math notation="LaTeX">S₁₁ </tex-math> and <tex-math notation="LaTeX">S₂₂ </tex-math> exceed 6.3- and 12.7-dB, respectively. The dc power dissipation is 183-mW ( <tex-math notation="LaTeX">Pdc </tex-math> ). From 217.5- to 225-GHz, the saturated output power <tex-math notation="LaTeX">Pₛₐₜ </tex-math> 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 <tex-math notation="LaTeX">Pₒᵤₜ </tex-math> , gain, and PAE are at 220-GHz operation. The 1-dB gain compression <tex-math notation="LaTeX">Pₒᵤₜ </tex-math> (OP <tex-math notation="LaTeX">1\,dB </tex-math> ) 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.