An image rejection down-converter for low-IF receivers in 130 nm CMOS

Implemented in 4.1 mm² in 130 nm CMOS, a dual-conversion image rejection down-converter applied to the WCDMA standard draws 13 mA from 1.8 V. Using an IF of 2.5 MHz, the WCDMA image rejection band is widened from between 0.58 MHz and 4.42 MHz to between 0.48 MHz and 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; NF is 10.8 dB. Typical IRR is 44.8 dBc, 46.5 dBc, and 47.5 dBc at -20°C, 25°C, and 80°C, respectively.