A 2.5W/mm High-Power Density V-Band Power Amplifier Using 150 nm GaN Technology Beyond fT

In this article, we present a V-Band power amplifier (PA) with a power density of 2.5 W/mm, which uses Fraunhofer IAF’s recently developed 150nm GaN HEMT technology and is designed well beyond the technology’s transition frequency (fT). This technology (GaN15) is based on established processing concepts and supports reliable operation at high rated supply voltages (VDS = 30 V). At the same time, the technology is carefully designed to minimize parasitic capacitances, thereby extending its frequency range towards the upper V-band and lower E-band. The presented two-stage two-way combining PA is designed to cover the 59-71 GHz band allocated for inter-satellite links (ISLs) in the V-band with an output power of more than 28 dBm. When biased at 25V, the PA produces a peak output power of 31.3dBm (1.35 W) with a power-added efficiency (PAE) of 14.7% at 62 GHz, resulting in a power density of 2.5W/mm at 2-dB gain compression. When biased at a reduced supply of 15V for efficient operation, the PA still produces a peak output power of 28.9dBm (0.78W) with a PAE of 18.9% at 59 GHz, resulting in a power density of 1.4 W/mm. These results demonstrate the potential of the used 150nm technology for the design of linear high-power amplifiers at the upper mm-wave bands.