Design Of Direct Digital Synthesizer Based On Multi-CORDIC Core Structure

Almost every complex electronic system needs a stable and accurate frequency synthesizer. As the modern technology like modern electronic communication, Radar, electronic countermeasures technology is developing fast, frequency synthesizer with wide frequency range, high frequency resolution, fast frequency switching and high stability is needed.In this dissertation, a multi-CORDIC structure direct digital synthesizer is proposed, which is partially based on the existing research by the former researchers. This new structure is simulated both in system level and RTL level. In order to prove the advantages of the new structure, some specifically parameters are compared between multi-CORDIC structure direct digital synthesizer and traditional CORDIC structure direct digital synthesizer.The results indicate that the new structure's output frequency range get n times improve, and the output frequency get better performance in low frequency. In order to get the high frequency, the circuit need to work with high clock frequency, so full custom design ASIC must be the best choice. But with a view to the high cost of manufacture and the long design cycle, the multi-CORDIC structure direct digital synthesizer is only implemented by FPGA. The testing result of Chipscope quite fit the requirement. Both The system& RTL level simulation and FPGA implement indicated that multi-CORDIC structure direct digital synthesizer can greatly improve the performance of frequency synthesizer.