Design Of Arbitrary Singal Generator Base On DDS

The Direct Digital Frequency Synthesis (DDS) is a kind of new frequency synthesis method. With the development of digital integrated circuits and microelectronic techniques, DDS exhibits its advantages day by day.The direct digital frequency synthesizer is a kind of fully digitized frequency synthesizer, which consists of the phase accumulators, the sine look-up table, the digital to analog converter, and the band-pass filter. It is of high frequency resolution, fast frequency switching speed, the ability to switch frequencies while maintaining constant phase.The dissertation firstly introduces the development of frequency synthesis techniques, and discusses the significance of realizing the direct digital frequency technique based on Field Programmable Gate Array (FPGA).Secondly, the principle and structure of DDS are introduced, then the paper analyses the spectrum characteristic of direct digital frequency synthesizer output. Especially, the spectrum characteristics of the phase truncation error and amplitude quantization error are discussed at length.Thirdly, the paper presents the structure of FPGA, at the same time introduces the open up system and design flow of FPGA. Then the paper expatiates on the method of how to produce Sine signal, especially on the step of frequency synthesis.