Design And Implementation Of The Microwave Frequency Source Based On DDS

With the rapid development of modern electronic systems, the demand ofmicrowave frequency source with excellent performance has been increasedsimultaneously. The performance such as frequency purity, frequency coverage,frequency step, phase noise etc, has been urgently raised. Microwave frequency sourcehas been widely used in communications, finance, electricity, radio, television,high-speed traffic, guidance, electronic warfare and other fields, it also has importantapplications in the defense field such as time and frequency, spacecraft monitoring andcontrol, cooperative engagement and precision strike.In this thesis, the basic theory of synthesis and the application in the atomic clockare researched, the structures of frequency source are proposed，the debugging andtesting methods for every functional module and the whole souce are given in details：1. To provide theoretical support for the issue, the novel first studied WorkingPrinciple of DDS and PLL, analyzed the output spectral quality through the two method,focusing on the reasons and solving means of all spurious and noise.2. Based on DDS, combined with PLL, mixer and multiplier, a method to realizethe frequency source is given, To get a high spurious suppression, low phase noise,highfrefquency resolution output, we insert a mixed DDS into a tracking phase-locked loop,To meet the decomposed indicators of every module, the detailed schematic analysis,component selection and circuit design are proposed. By utilizing modern integrated IC,not only the difficulty of the implementation is reduced, but also can achieve a purierspectrum and higher resolution frequency. The frequency source can convenient changevarious states through the computer serial port, and the interface is friendly.3. The debugging and testing methods for high-performance microwave frequencysource, the debugging key points and the reason of the problem are analyzed, themeasured figures are given. The experimental results show that the technical solutionscan meet the target requirements.The successful realization of the microwave frequency source plays an importantfor the development of atomic clock, and can also be widely promoted in otherelectronic systems.