An Ultra Compact Watt-Level Ka-Band Stacked-FET Power Amplifier

An ultra-compact watt-level Ka-band monolithic microwave integrated circuit (MMIC) power amplifier (PA) is demonstrated using a 0.15 μm Gallium Arsenide (GaAs) stacked field effect transistor (stacked-FETs) configuration. The fabricated PA exhibits 31.5 dBm output power, 17 dB gain and 33% power added efficiency (PAE). The bandwidth is from 26 GHz to 31 GHz. The PA achieves 0.7 Watt/mm
²
power density at 28 GHz. To the best of our knowledge, this PA achieves the highest power density among reported GaAs Ka-band PAs.