Noise in Current-Commutating Passive FET Mixers

摘要

Noise in the mixer of zero-IF receivers can compromise the overall receiver sensitivity. The evolution of a passive CMOS mixer based on the knowledge of the physical mechanisms of noise in an active mixer is explained. Qualitative physical models that simply explain the frequency translation of both the flicker and white noise of different FETs in the mixer have been developed. Derived equations have been verified by simulations, and mixer optimization has been explained.