Second-Order Intermodulation in Current-Commutating Passive FET Mixers

摘要

Amplitude-modulation detection in the mixer plagues the performance of the zero-intermediate-frequency receiver by downconverting the envelope of amplitude modulated blockers to baseband where the desired channel is after downconversion. Simple equations based on physical mechanisms of second-order intermodulation generation have been derived which can predict the IIP2 of the current-driven passive mixer accurately. Derived equations have been verified by SPECTRE and SPECTRE-RF simulations, and mixer optimization has been explained.