A highly linear 84 GHz low noise amplifier MMIC in AlGaN/GaN HEMT technology

AlGaN/GaN-based high electron mobility transistors, when scaled to small gate lengths, may exploit the material´s high speed properties to achieve operating frequencies in the high millimeter-wave frequency range. Besides power amplification, these transistors can also be used to implement low noise amplifiers, which profit from the high breakdown voltages in terms of amplifier linearity and robustness. This paper presents the design, implementation and measured performance of a 84 GHz low noise amplifier MMIC in a new AlGaN/GaN on s.i. SiC HEMT technology with 100 nm gate length and maximum cutoff frequencies f_T and f_max of 80 and >;200 GHz, respectively. The amplifier achieves over 25 dB gain and 5.6 dB noise figure at 84 GHz. At a drain bias of 10 V, its output-related 1-dB compression point lies at +15 dBm, well beyond that of competing semiconductor technologies.