A FET propagation effects

A field-effect transistor constitutes a propagation structure along its gate width. Telegraphists equations are solved for this structure. One deduces from this the effect of the propagation on the transistor Z-parameters which can be taken into account in electric simulations and which may improve the use of long transistors at lower frequencies and of short transistors at higher frequencies [1]. New elements have been added to the equivalent circuit in order to take into account the propagation phenomena.