Low-noise high electron mobility transistors for monolithic microwave integrated circuits

High electron mobility transistors (HEMT's) for monolithic microwave integrated circuits have been fabricated that have demonstrated excellent performance. External transconductance of 300 mS/mm is observed and noise figures of 1 and 1.8 dB with associated gains of 16.1 and 11.3 dB at 8 and 18 GHz, respectively, have been measured. These are comparable to the best reported noise figures for either HEMT's or MESFET's and are the highest associated gains reported for such low-noise figures. Analysis of these devices indicates that further improvements in these results is possible through optimization of HEMT layers and fabrication technology to reduce gate-source parasitic resistance.