Accurate Noise Modeling of HEMT for Low-Noise Applications

A novel physical device model was developed for designing a low-noise-application-oriented HEMT structure and modeling a high-frequency noise characteristic of HEMT. To calculate accurate noise figure as a figure-of-merit indicating the high-frequency noise characteristics, two factors were considered based on Ando´s model: (1) The parasitic effects which are more dominant at higher frequency, including a gate-to-drain shunt feedback capacitance and a gate resistance, were taken into account. (2) The electron saturation velocity was assumed to depend on the gate length. Through the above two modifications, we calculated sheet carrier density, DC, RF parameters and noise figure (NF)