Wide-band 0.25μm CMOS passive mixer

This paper describes a wide-band resistive ring mixer fully integrated in 0.25 mum CMOS process. This mixer exhibits broadband RF impedance matching with return loss better than -10 dB from 2.2 to 8.3 GHz, and better than -15 dB from 3 to 6.2 GHz. The best conversion loss (CL) of 6.4 dB is achieved at 3.2 GHz. The input P1dB is better than 4 dBm, and the IIP3 is better than 11.4 dBm over the entire RF bandwidth of 2-9 GHz. Compared to other published CMOS wide-band resistive mixers, this mixer achieves the best linearity between 2 and 9 GHz. In addition, with a small gate bias a moderate CL is achieved at very low LO power levels.