This article presents a low IF mixer featuring metal-oxide-semiconductor devices in the rf and the active load stages for DCS applications which have been optimized with respect to the supply voltage (2.2 V), current consumption (<10 mA), gain (10 dB), linearity (IIP3 = 8.5 dBm), and noise (DSB Nf = 13 dB at 100 kHz). Special attention has been paid to the identification of the noise mechanisms.