Simple and accurate extraction methodology for RF MOSFET valid up to 20 GHz

Abstract

An accurate and simple parameter extraction technique for deep submicron MOSFETs using a conventional MOSFET model with three terminal resistances for the gate, source and drain, as well as a simple substrate coupling network and a non-reciprocal capacitor is proposed. This extraction technique utilises both Z and Y parameter analysis on the proposed small-signal equivalent circuit. RF simulation is carried out using the BSIM4 DC core model with the extracted extrinsic components. Analytical equations are derived for all the RF parameters and a linear regression technique is used to extract the parameters. Transcapacitance is utilised in the model to ensure charge conservation and good fitting of the Y21 and Y12 parameters. The extracted and optimised RF parameter values are in close agreement, which implies that little or no optimisation is required using this technique. Hence, this extraction methodology can be implemented easily for RF MOSFET modelling. Excellent agreement has been obtained between the simulated and measured results up to 20 GHz.