A DDFS Driven Mixing-DAC with Image and Harmonic Rejection Capabilities

Abstract

The proposed DDFS-driven mixing-DAC consists of several parallel-connected Gilbert cells driven directly by the binary and thermometer DDFS data compromise between power-dissipation and harmonic-rejection performance is achieved with 5b binary LSBs and 5b thermometer MSBs segmented mixing-DAC. The 2.8-to-3.2 GHz DDFS sampling frequency is selected such that it provides in excess of two samples per cycle up to 1 GHz, while the LO sampling spurs (fsplusmnfL0) are always outside the receiver desired frequency band. It is dynamically adjusted for each received channel to minimize in-band DDFS induced spurs.