Comparative study of two types of exciting sources based on DDS technology

    LIU Yanª²Yong, DONG Xiuª²Zhen, YOU Fuª²Sheng, SHI Xueª²Tao, JI Zhenª²Yu

    Department of Medical Electronic Engineering, School of Biomedical Engineering, Fourth Military Medical University, Xi¬ðan 710033, China

    ¡¾Abstract¡¿ AIM: To compare the performance of two exciting sources based on direct digital synthesis (DDS) technology and to present some advice for the future system design. METHODS: The exciting source based on DDS chip was designed and was compared with the exciting source based on field programmable gape array (FPGA) chip on the spectrum performance and flexibility. RESULTS: In spectrum performance, there were fewer and smaller stray signals in the FPGA exciting source than that in the exciting source based on DDS chip. In regarding flexibility, the exciting source based on DDS chip was superior. CONCLUSION: The two types of exciting sources have their own advantages and choice should be made by need. As our experiment needs high flexibility, we have chosen the exciting source based on DDS chip. ......