Improved small-signal modeling of RF Si MOSFETs

We investigate non-physical phenomena occurring in extracting MOSFET parameters of a conventional small-signal model in detail. In order to eliminate these phenomena, an improved small-signal model connecting the drain-bulk junction capacitance into the external source has been developed. This improved model allows us to extract frequency-independent parameters in the wide range of frequency while maintaining the physical validity. Good agreement between measured and modeled gain plots is achieved in the frequency range of 0.5 to 39.5 GHz.