Fundamental performance limits and scaling of a CMOS passive double-balanced mixer

In this paper, fundamental performance limits and scaling of a double-balanced passive mixer are examined. Analysis of the passive double-balanced mixer will show how its performance metrics are directly affected by the down-scaling of the transistor gate length, L_G. We analyze the performance in terms of conversion gain (G_C), 1-dB compression point (P_1-dB) which we derive, and SSB Noise Figure (NF). We will show that as CMOS process technology evolves, the double-balanced passive mixer architecture will become more favorable and yield improved performance. This is verified through simulation and modeling results for mixers designed in CMOS 350 nm to 32 nm technology. We introduce a mixerpsilas figure-of-merit (FOM_MIXER) to compare performance with technology scaling. Circuit designers and system architects can use this paper to find a suitable process technology that will meet their specifications.