An image-rejection down-converter for low-IF receivers

Implemented in 4.1 mm/sup 2/ in 130-nm CMOS, a dual-conversion image-rejection down-converter applied to the wireless code-division multiple-access (WCDMA) standard draws 13 mA from a single 1.8-V power supply. Using an IF of 2.5 MHz, the WCDMA image-rejection band is widened from 0.58-4.42 MHz to 0.48-5.2 MHz-a bandwidth ratio of 10.8-to accommodate process, voltage, and temperature variations in high-volume production. Ten samples are measured and fully characterized: average image-rejection ratio (IRR) is 46.6 dBc, gain is 12 dB, and noise figure is 10.8 dB. Typical IRR is 44.8, 46.5, and 47.5 dBc at -20/spl deg/C, 25/spl deg/C, and 80/spl deg/C, respectively.