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 2.5W/mm, which uses Fraunhofer IAF’s recently developed 150nm GaN HEMT technology and is designed well beyond the technology’s transition frequency $( f_{T})$. This technology (GaN15) is based on established processing concepts and supports reliable operation at high rated supply voltages $( V_{DS}\,=30\mathrm{V})$. 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 59-71GHz band allocated for inter-satellite links (ISLs) in the V-band with an output power of more than 28dBm. When biased at 25V, the PA produces a peak output power of 31.3dBm (1.35W) with a power-added efficiency (PAE) of 14.7% at 62GHz, 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 59GHz, resulting in a power density of 1.4W/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.