An improved model for four-terminal junction field-effect transistors

The junction field-effect transistor (JFET) has isolated top- and bottom-gate terminals and therefore is useful for signal mixing applications. Existing models for the four-terminal JFET often have the same form as the three-terminal JFET model, however, in which only a single pinch-off voltage is used to describe the current-voltage characteristics. In this paper, a more general four-terminal JFET model is developed. Two different pinch-off voltages are involved in the improved model to account more comprehensively for the effects of both depletion regions associated with the top- and bottom-gate junctions. Results simulated from a device simulator are also included in support of the model.