Analysis and optimization of IIP2 in CMOS direct down-converters

Abstract

Two mechanisms are responsible for second order intermodulation in CMOS down-converters: RF self-mixing and device non-linearity and mismatches. An intuitive model and analytical expressions are provided for both of them. A down-converter prototype, drawing 3.2 mA from a 1.8 V supply, part of a fully integrated 0.18 /spl mu/m CMOS UMTS receiver front-end shows 66 dBm IIP2 and 16 dBm IIP3.