Optimal second-order small-signal model for long- and short-channel three-terminal MOSFET/MODFET wave equation

An optimal second-order small-signal model is developed for the long-channel three-terminal MOSFET/MODFET wave equation. The resulting Y parameters admit the correct fourth-order frequency power series expansion and exhibit a graceful degradation at high frequencies compared to a previously reported second-order model. This model can be integrated in the velocity-saturated MOSFET/MODFET equivalent circuit and is demonstrated to greatly improve the frequency range of validity of this short-channel model. The excellent results obtained demonstrate the validity of both the equivalent-circuit synthesis procedure and the correctness of the equivalent circuit proposed.>