A new approach to distributed modeling of MESFETs

Distributed modeling of transistors has important role in analysis of their signal and noise performance especially at high frequencies. Because of ohmic resistance of the contacts (gate, source and drain contacts), the applied voltages drop along the contacts. The local voltages are not the same for different points of the drain and source contacts. Therefore when the lumped transistor is sliced in to subtransistors, the parameters of these subtransistors will not be the same. In this paper, a new approach for distributed modeling of a MESFET transistor is presented. In the proposed method, voltage drop along the contacts were taken into account and source contact became distributed. Also the parameters of subtransistors were calculated and diffusion noise for this modeling was considered. The model is based on gradual channel approximation.