Analysis of field effect transistors with arbitrary charge distribution

Abstract

Solutions of field effect equations in which carrier density and space-charge distributions are considered in general form show that the LF terminal characteristics are not strongly dependent on the shape of the distribution curves. General expressions for mutual transconductance, output conductance, junction capacitance and current amplification are derived as functions of the depletion layer thickness at the device boundaries. These expressions are not explicitly dependent on charge distribution. Relationships between the small-signal and dc terminal characteristics depend on the shape of the charge distribution curves but cannot be varied by more than a factor of two. The shape of the device is shown to have secondary importance.