Simplified analytical expression for calculating noise figure of HEMT gate mixers

摘要

A simplified analytical expression for calculating noise figure of HEMT gate mixers is presented based on superposition method. The contributions of each noise source have been presented. The non-linear behavior of the transistor expressed by the transconductance profile is used to evaluate the noise figure versus LO power. This study is applied to a HEMT gate mixer, tested at 28.5 GHz radio frequency and 4 GHz intermediate frequency. The predicted and the measured noise figures are in good agreement.