The effect of multiple gate for P1dB and PAE of AlGaAs/InGaAs HEMT

The impacts of numbers of gate fingers on large signal of High Electron Mobility Transistor (HEMT) were studied in this paper. The analysis was carried out measurement using Maury Automated Tuner System (ATS) at frequency of 2.4 GHz and 5.8 GHz. The measurement results shows that the transistor that has higher number of gate fingers is less preferred for high P1dB compression and Power Added Efficiency (PAE) performance. This is due to the parasitic existed in larger transistors that cause P1dB and PAE to drop significantly. Moreover, higher input impedance of the transistors further contributions to the degradation of these performance indicators. Finally, the optimum transistors is proposed.