Abstract
In this contribution, we analysis the small-signal admittance and the corresponding noise of the high electron mobility transistors under a continuation branching of the current between channel and gate. The analytical approach takes into account the linearization of the 2D Poisson equation and the drift current along the channel. The real part of admittance and the noise spectra exhibit resonances in high frequency associated to the oscillations in the channel. The appearance of the resonances is discussed as function of the geometrical channel parameters (length, thickness and doping concentration).