Direct extraction of the channel thermal noise in metal-oxide-semiconductor field effect transistor from measurements of their rf noise parameters

This article presents an extraction method to obtain the channel thermal noise in metal-oxide-semiconductor field effect transistor (MOSFETs) directly from the dc, scattering parameter and rf noise measurements. In this extraction method, the transconductance ${\mathrm{(g}}_m\mathrm{),}$ output resistance ${\mathrm{(R}}_{\mathrm{DS}}\mathrm{),}$ and source and drain resistances ${\mathrm{(R}}_S$ and $R_D)$ are obtained from dc measurements. The gate resistance ${\mathrm{(R}}_G)$ is extracted from scattering-parameter measurements, and the equivalent noise resistance ${\mathrm{(R}}_n)$ is obtained from rf noise measurements. This method has been verified by using the measured data of a 0.36 μm n-type MOSFET up to 18 GHz. Comparisons between simulated and measured characteristics of noise parameters versus frequency are also presented.