Super-low-noise HEMT based on new HEMT noise model

Using a two-dimensional device simulation, we clarified why HEMT's have a superior low-noise performance. The new HEMT noise model, which considers the cooling effect on the electron temperature, indicates that higher sheet carrier density leads to lower noise power. Using this noise model, super-low-noise HEMT's with a 0.15-μm T-shaped-gate were fabricated on an In_0.49Ga_0.51p/In_0.25Ga_0.75As heterostructure. The device achieved an optimum noise figure of 0.42 dB with an associated gain of 13.5 dB at 12 GHz.