AN IMPROVED MODEL FOR 4-TERMINAL JUNCTION FIELD-EFFECT TRANSISTORS

The junction field-effect transistor (JFET) has isolated top- and bott om-gate terminals and therefore is useful for signal mixing applicatio ns. Existing models for the four-terminal JFET often have the same for m as the three-terminal JFET model, however, in which only a single pi nch-off voltage is used to describe the current-voltage characteristic s. 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 regi ons associated with the top- and bottom-gate junctions. Results simula ted from a device simulator are also included in support of the model.