Linearity by Synthesis: An Intrinsically Linear AlGaN/GaN-on-Si Transistor with OIP3/(F-1)PDC of 10.1 at 30 GHz

Abstract

In today’s radio-frequency (RF) systems, linearity of amplifiers is a key concern due to presence of significant numbers of in-band interferers in the crowded spectrum. GaN high electron mobility transistors (HEMTs) can provide low noise front-end amplifiers, but state-of-the-art GaN HEMTs still possess non-linearity exhibited by a transconductance, g m , roll-off from its peak due to the dynamic source access resistance and other factors [1] . The dynamic range figure-of-merit (DRFOM) for low noise amplifiers (LNAs) [2] , OIP3/(F-1)P DC , where OIP3 is the output 3 rd -order intercept point (OIP3), P DC is the DC power, and F is the noise factor, is still limited to ~1.7 in mmwave GaN transistors [3] . Joglekar et al. attempted to increase linearity by using different Fin widths resulted in flat g m of ~2 V [1] ; linearity figures of merit were not properly assessed. Here, we demonstrate a novel method to synthesize g m plateau over a 6 V gate overdrive and a record DRFOM of 10.1 in GaN HEMTs at 30 GHz.