AlN/GaN/AlGaN-on-Si HEMT Achieving 1.3 W/mm at 5 V for 5G FR2 Handsets

This Letter reports a double heterostructure (DH) AlN/GaN/AlGaN-on-Si HEMT, which has been proposed, for low voltage (LV,≤ 5V) RF operation. The proposed transistor shows excellent DC (Idmax =1.9A/mm,gₘₘₐₓ =0.66S/mm) and RF small-signal characteristics (fT/fₘₐₓ =145/195 GHz). Continuous-wave (CW) load-pull measurements at 30 GHz yieldPₛₐₜof 0.6 (1.3) W/mm at Vdsof 3.5 (5) V, and peak power-added efficiency (PAE) of 43% (42%). To the best of the authors’ knowledge, thePₛₐₜvalues are the highest reported for LV GaN-on-Si HEMTs in 5G FR2, despite the use of conventional alloyed contacts and a gate length (Lg) of 120 nm. Furthermore, among published LV GaN-on-Si HEMTs, the proposed transistor achieves a desired combination of saturation velocity (v ₛₐₜ) and knee voltage (Vₖₙₑₑ), which are critical factors for LV power amplification. The results reflect the promising potential of the proposed heterostructure to achieve high transmit power in 5G FR2 handsets.