A 4-W Ka-Band High-Efficiency 0.15 μm GaAs Stacked Power Amplifier Design

This paper introduces a two-stage 4 W Ka-band power amplifier (PA) operating between 23 and 28 GHz. Designed using commercially available 0.15 μ m GaAs pHEMT technology, the PA features a stacked FET topology to increase output power without expanding the chip area. This paper presents the first demonstration of a high-power GaAs power amplifier with a saturated output power of 4 W in the Ka band, utilizing a stacked-FET architecture and parallel combining. With an 8 V power supply, the simulated PA achieves a saturated output power of 4 W by combining eight stacked-FET cells. The PA has a large-signal gain of 22 dB and power-added efficiency (PAE) of 33 % at 25 GHz, while its chip area is 9.86 mm². To the best of the authors' knowledge, the simulated PA has the highest PAE among the simulated GaAs PAs reported in the Ka band and achieves a saturated output power greater than 2 W.