依据直接数字频率合成技术(DDS)工作原理,在simulink软件搭建系统仿真模型输出正弦信号,在此基础上实现了两种压缩ROM查询表数据量的方法来抑制杂散波,并把这两种压缩方法相结合使得压缩比达到了1∶42.67,有效减少了查询表的规模,降低了对DDS资源的占用.另一方面提出了一种基于DDS芯片AD9851和AT89S52单片机的正弦信号源设计方案,给出了该方案的相关硬件接口和软件程序,经过对实际PCB板的测试,实现了1 Hz～50 MHz的正弦信号输出,该正弦信号源可应用在不同的高频领域.%According to the operating principle of direct digital frequency synthesis (DDS),this paper builds system simulation models to output sinusoidal signal in simulink software.In this model,two different methods of compressing ROM query table data volume are used to suppress spurious waves and the combination of these two compression methods makes the compression ratio down to 1∶ 42.67,effectively reducing the size of the query table and the occupation of DDS resources.On the other hand,based on DDS chip AD9851 and AT89S52 single chip microcomputer,this paper proposes a design scheme of sinusoidal signal source and also presents the relevant hardware interface and software program.After the test on the actual PCB board,we have successfully output the 1 Hz～50 MHz sine signal and the source of which can be used in different high frequency fields.
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