End-to-End Direct Digital Synthesis Simulation and Mathematical Model to Minimize Quantization Effects of Digital Signal Generation

Abstract

Direct digital synthesis (DDS) architectures are becoming more prevalent as modern digital-to-analog converter (DAC) and programmable logic devices evolve to support higher bandwidths. The DDS architecture provides the benefit of digital control but at a cost of generating spurious content in the spectrum. The generated spurious content may cause intermodulation distortion preventing proper demodulation of the received signal. The distortion may also interfere with the neighboring frequency bands. This article presents the various DDS architectures and explores the DDS architecture which provides the most digital reconfigurability with the lowest spurious content. End-to-end analytical equations, numerical and mathematical models are developed to determine the location and power levels of spurs. Afterwards, the analytical equations, numerical and mathematical models are shown to be consistent with the experimental data. A developer can use the information to design a DDS architecture that meets their minimum requirements.