A High-Frequency Small-Signal Model for Four-Port Network MOSFETs

A high-frequency small-signal model for a MOSFET is proposed considering the parasitic capacitances associated with each terminal that is critical in the design of high-frequency amplifiers. The proposed model allows in obtaining a closed-form expression for poles and zeros due to parasitic elements along with the conventional poles and zeros. This model gives an additional degree of freedom in choosing the location of poles and zeros to improve the frequency response. The proposed high-frequency small-signal model for MOSFET is validated in simulation by implementing a high-frequency voltage follower in 0.18-μm CMOS process. The proposed model shows the existence of a zero in a voltage follower that is introduced by the parasitic elements at high-frequencies and it is validated with implementation.