Key points are not available for this paper at this time.
The authors have demonstrated 0.25 µm gate-length Al0.5Ga0.5N/GaN MODFETs on sapphire substrates which exhibit CW output power densities > 3 W/mm at 18 GHz, the highest reported to date for microwave FETs in the K band. This confirms the promise of the high Al-content AlGaN/GaN MODFET structure.
Wu et al. (1997) studied this question.