POTENTIAL FEEDBACK IN FIELD-EFFECT DEVICES

One-dimensional potential profile inside the static induction transistors is analyzed. The potential profile rearranges itself due to negative feedback by a change in gate or drain voltage. The potential barrier shows a nonlinear variation with drain voltage and it tends toward nonexistence as the drain voltage increases, i.e., negative feedback reduces the barrier height. This negative feedback is an important factor in determining the barrier height, which in turn decides the static characteristics of the field-effect devices. Generalized curves of potential profile for field effect, static induction, and analog transistors are presented where secondary effects are neglected. This explains the vacuum-pentode- or vacuum-triode-type characteristics in the unipolar devices.