The Research & Realization Of Direct Digital Synthesizer With Multifunction Based On AD9852

The signal synthesizer is one of the very important members in modern electronic system. It is widely applied in many fields such as communication,navigation,radar,measure and control. Then frequency Synthesis is the most important technique in research of signal synthesizer. The development course of frequency Synthesis is presented in this paper, the merit,demerit and theory of three kinds of frequency Synthesis are discussed, and characteristics of Direct Digital Synthesis(DDS) are summarized. After an analysis of kinds of popular DDS chirps, the project of multifunctional direct digital synthesizer on basis of AD9852 is put forward. Then the hardware structure and software design of the synthesizer are mainly described, the system makes AD9852,DSP,PLD,DDS and C51 work well in phase, so that it can realizes much complex function such as digital modulation,analog modulation. The hardware of the signal synthesizer system consists of three blocks, those are mainboad based on AD9852,low frequency signal module of multi-waves, keyboard and LCD display module. Software of the system mainly focuses on the design of embedded program based on DSP and C51 including control ,data processing,communication, and so on. However it is the most important to control AD9852 and exert its all potential, and it is emphasized in the paper. Finally testing result of the synthesizer is analysed and the method of improvement is presented.