A direct-to-digital frequency translating sigma-delta based receiver

Abstract

In this brief, a new form of direct conversion sigma-delta modulator-based receiver is presented. Distortion reduction is obtained as a result of including the down conversion mixers into the sigma-delta loop. The use of an equivalent low-pass model simplifies the analysis and design. The proposed architecture is very attractive for integration into any suitable CMOS technology. Simulation of a discrete equivalent model shows agreement with predicted performance.