AbstractA new approach for physical one‐dimensional FET modeling is presented, which is based on an analytical velocity overshoot approximation. As an application, an improved description of short‐channel GaAs‐MESFETs is shown. This simulation is equivalent to the use of a saturation velocity, which depends not only on gate length but also on bias. The presented approach is based on a new criterion subdividing the channel, which may also be used in simulation of other types of FETs. A comparison of the proposed model with experimental data of the DC behavior and numerical results shows the necessity of taking surface effects and substrate currents into account. © 1993 John Wiley&Son