Spurious Signals Analysis of Direct Digital Frequency Synthesizer and Spur Reduction Techniques
Pan Ming-hai · Dianzi qijian · 2007
The spurious signals in DDS generated by phase-truncation,amplitude-truncation and the digital-to-analog conversions are analyzed,and their frequency spectra characters and distributing rules are studied.The conclusion presents phase truncation is the critical source of spurious signals spectrum in DDS.A new method selecting the clock frequency correctly is proposed.It is used to eliminate spur caused by phase truncation.Then the author presents a scheme of concatenation structure to reduce spurs of output signal in designing project.Finally,the computer simulation indicates that the scheme is feasibility.