Analytical i.g.f.e.t. model including drift and diffusion currents

An analytical i.g.f.e.t. model including drift and diffusion currents along the channel is developed. The theory, which is based on a gradual-channel approximation, is essentially equivalent to the double-integral formula by Pao and Sah, which provides correct results both in weak and in strong inversion. I.G.F.E.T. characteristics such as drain current, transconductance and output conductance are analytically expressed against the surface potential at the source and drain edges of the channel, which can be numerically evaluated in a few iterative steps. The model therefore seems suitable for c.a.d. applications.