Common-source cold-FET used to validate noise figure measurements and on-wafer FET noise parameters

This work proposes the use of a common-source cold-FET with gate forward biased to validate the noise figure measurements and the noise parameters of on-wafer transistors. Since a common-source cold-FET behaves as an attenuator, its noise figure and noise parameters can be determined from S-parameters measurements. Three methods for determining the noise parameters of the common-source cold-FET are investigated. The first one uses the noise correlation matrix for passive devices (the S-parameters), the second one is the tuner method and the third one is the F50 method. The noise figure measured and the noise figure computed from S-parameters agree quite well. The noise parameters extracted with the tuner method and the F50 method show good correlation with the noise parameters computed with the S-parameters. These results validate both the noise figure measurements and the noise parameters extraction.