A baseband-65GHz High Linearity-Bandwidth GaN LNA using a 1.7A/mm High Current Density ScAlN based GaN HEMT Technology

This paper describes the design and measured performance of a baseband-65GHz high linearity-bandwidth GaN MMIC low noise amplifier based on a 90nm ScAlN GaN HEMT technology. The GaN technology is characterized by a peak fT of 130 GHz and a high Idmax current density of 1.7A/mm enabled by a ScAlN barrier. The LNA is comprised of a cascode distributed amplifier with a low-noise active gate-termination. The amplifier achieves 10.8-13.9dB of gain and a NF of 1.65-2.5dB is obtained from 1 to 30GHz, < 3 dB up to 43GHz, and < 4.1dB up to 50GHz. IP3 of 35.3-37.6 dBm was also obtained over a 2-45GHz frequency. Due to the high fT and Idmax of ScAlN HEMTs an IP3-BW of 152.5 W-GHz was achieved which is believed to be the best reported for GaN DAs without circuit linearization techniques. The ability to provide low noise and high linearity over a broad band from a single MMIC is attractive for future reconfigurable radio architectures.