An Improved Analog Waveforms Generation Technique using Direct Digital Synthesizer

In many kinds of equipment, it is important to produce readily control accurate waveforms of various frequencies and profiles such as agile frequency sources with low phase noise and low spurious signal content for communications, and simply generated frequency for industrial and biomedical applications. A direct digital synthesizer (DDS) provides many significant advantages over the PLL approaches such as Continuous-phase switching response, fine frequency resolution, Fast settling time, and low phase noise are features easily obtainable in the DDS systems. The aim of this paper starts from the DDS circuit structure and discusses the design method of DDS based on VHDL in detail.