Modélisation des Caractéristiques du GaAs MESFET

A NEW MODELING OF THE CHARACTERISTICS OF GaAs MESFET'S: A new approach for I-V standard model is proposed. This approach allowed to conceive applicable model for MESFET's operating in the turn-one or pinch-off region, and valid for the short-channel and the long-channel MESFET's, in which the two-dimensional potential distribution contributed by the depletion layer under the gate is obtained by conventional 1D approximation. The drain current is decomposed into two components; the first is due to the conduction current flowing through the conduction channel, and the second component is a result of the current flowing through the space charge region resulting from the injection of the channel electrons into this last region. Moreover, comparison between the proposed analytical model and the experimental data are made and good agreement is obtained. In the end, this model is applied to estimate the cut-off frequency of the MESFET-GaAs from these static characteristics. This estimation is based on the theoretical calculation of the transconductance and the gate capacitance of the device