Spurious mechanisms and debugging in direct digital synthesis

While the technique of direct digital frequency synthesis (DDFS) is well known, the mechanisms active in the generation of non-harmonic spurious output signals are not so well known. Here the significant spurious generating processes active in a DDFS design are illustrated. Use of this information in debugging a DDFS design to fundamentally reduce power in spurious signals is discussed. Thus this work specifically excludes dithering, a spurious power spreading process, from the techniques considered.