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.