GAN MICROWAVE ELECTRONICS

In this paper, recent progress of AlGaN/GaN-based power high-electron- mobility transistors (HEMT's) is reviewed, Remarkable improvement in p erformances was obtained through adoption of high Al contents in the A lGaN layer. The mobility in these modulation-doped structures is about 1200 cm(2).V-1.s(-1) at 300 K with sheet densities of over 1 x 10(13) cm(-2). The current density is over 1 A/mm with gate-drain breakdown voltages up to 280 V. F-t values up to 52 GHz have been demonstrated. Continuous wave (CW) power densities greater than 3 W/mm at 18 GHz hav e been achieved.