Model of the drain current saturation in long-gate JFETs and MESFETs

A model of the drain current in the long-gate JFET and MESFET is proposed in which the electron velocity saturation is not mandatory-requirement for the drain current saturation. According to it the drain current saturation is result of the screening of the field, which the drain voltage creates, by the gates, and the appearing of the diffusion component of drain current. Silvaco simulation confirms the proposed model. Approximate analytical expressions for the drain current before the channel pinch-off and saturation of current after it was obtained.