Design Of DDS Based On STAM Algorithm

The technology of Frequency synthesis which contains of Direct Synthesis,Phases-locked Synthesis and Direct Digital Synthesis is widely used in the field ofcommunication, radar, electronic confrontation, aeronautics, instrument and so on.The direct digital frequency synthesizer is a kind of fully digitized frequencysynthesizer, which based on digital sampling technology and consists of phaseaccumulator, ROM look-up table, digital to analog converter, and low pass filter. Ithas the advantages of high frequency resolution, fast frequency switching speed, theability to maintaining constant phase while switch frequency, low phase noise.Firstly, the dissertation reviews the history of frequency synthesis techniques,and application in all fields, and analysis the feasibility and significance of realizingthe direct digital frequency technique based on Field Programmable GateArray(FPGA); Secondly, it analysis the structure of the direct digital frequencyanalysis and the relationship between input and output. Thirdly, it introduces theFPGA devices made by Altera company and the development software and designprocess, Then describes the characteristics of the pipeline technical, the theory ofSBTM algorithms and STAM algorithms evolved by SBTM algorithms, and uses it inthe realization of the sine function, the STAM algorithms is introduces and applied tothe performance of sine function on the FPGA. Then, it designs each module of DDSsystem by VHDL language and integrates simulation.After comparison and analysis, Look-up table module based on STAMalgorithms can occupy a smaller chip resources, the hardware circuit needed is moresimple, avoids the phase truncation error, the accuracy of the results is in the scopecontrolled, and48frequency control word enables the scope of frequency synthesischange broader.