Research And Design Of Waveform Generator Based On DDS And FPGA Technology

Signal generator has become all-purpose instrument from very walk of life. The level of design a signal generator is also continuously improve. Direct Digital Frequency Synthesis (DDS) is the rapid development in recent years as a frequency synthesis technique. It has high resolution, frequency conversion speed, phase continuous, and a wide variety of waveform. It has been widely sued in communication apparatus, medical appliance, instructional instruments, radar signal source and other fields.After in-depth understanding and analysis of the principle of DDS, the author used DDS chip AD9854 and FPGA chip EP1C6Q240C8 to implement and simulate a sine signal generator and an improved arbitrary waveform generator respectively. This issue mainly includes two aspects as followed:(1) According to the subject requirements, AD9854 chip of AD company had been used as the core chip of the waveform generator, and a FPGA chip EP1C6Q240C8 was also selected as a DDS chip logic programming controller. The schematic diagram and PCB board of the DDS signal source circuit were designed. By software programming and hardware debugging, a sine signal generator was implemented.(2) In the fourth chapter, EP1C6Q240C8, a Field Programmable Gate Array (FPGA) chip has been used for design a signal generator what used to top-down design method, pipeline and parallel-design structure. Phase-locked loop, mode control and DDS are the three parts of this design. Through programming and simulation the arbitrary waveform generator can achieve signals such as sine wave, linear frequency modulation continuous wave and nonlinear frequency modulation continuous wave, as well as to achieve digital signal 8ASK,8FSK and 8PSK modulation. This signal generator from running speed, resource usage and power dissipation, have reached a very high standard.