Development And Implementation Of Universal Communication Clock Source

DDS is a new generation of frequency synthesis technology after DS and IS. It is originated from the concept of phase, with the full digital realization of the hardware. It has many outstanding features gaining fast development in the recent tens of years. It is extensively applied in the fields of communication, radar, electronic confrontation etc. This paper has carried on the relative systematic analysis on the DDS.This paper has elaborated the basic structure, working principle, and the research and development situation in and abroad of DDS. It points out that the bad function of spurs and large energy consumption are the main reasons for the limitation of appliance of the DDS technology.According to the research and development requirements, the chosen target to be analyzed is the actual spectrum performance curve of the DDS product AD9852 in ADI company. With regard to different time frequency and the multiplied number of the internal timing machine of DDS;the spurs and phase noises performance will be different. In these circumstances, Except for some conditions that create spurious sources because of phase truncation and amplitude truncation, there is also the other main source of spurs, that is, the spurs caused by the non-linearity of the DDS, and the beat frequency of the output signal, its harmonics and clock leakage. The design of the single board is for one test board. The primary aim is to produce the altering frequency. The required wave should be the sine wave or square wave. According to these requirements, AD9852 is chosen;the key is to realize the production of jitter and wander, which has been extensively applied practically. At last the author gives his own thoughts on how to measure the loop bandwidth of PLL by the produced jitter source.This paper emphasizes on the realization of the hardware and software of the single board, through the analysis on a large amount of experimental data and pictures, the appropriateness of the appliance of this single board in practical use is proved. Of course there are some deficiencies in the design which will be shown in the paper.