Research And Realization Of A High-performance Frequency Synthesizer Based On DDS Hybrid PLL

In this dissertation we mainly research on frequency synthesis techniques. The subject derives from the project of "The research of relay-satellite techniques". After comparing kinds of technique of digital frequency, we choose the direct digital frequency synthesis (DDS) hybrid phase locked loop (PLL) solution to produce high-performance and functionally-integrated signal with low phase noise and spurious.First, we introduce the structure, basic principle of phase locked loop and frequency spectrum of direct digital frequency synthesizer, especially analyze some sources of spurious signals in DDS and phase noise in PLL. In the light of their properties, we analyze the influences generated by the phase truncation and amplitude quantization of sinusoid and by the transform error of DAC, also provide their distribution pattern in the output spectrum.Then we discuss in detail how to select PLL frequency synthesis design scheme, and emphasize the analyse of the generation of phase noise and spur in the scheme. Give the design methods of common active filters of DDS hybrid PLL frequency synthesizers. Put forward frequency synthesis method and also a revolution in the frequency synthesis techniques.Finally, we make a circuit adopting the method of DDS hybrid PLL. Using this method in the subject has many advantages: the merits of DDS such as super fine frequency resolution, high frequency accuracy, easy-programmed etc. combined with the excellent character of narrow-band tracing filter of PLL. Give some qualitative conclusions on spurious suppression and phase noise debasing. Offer some technical references to application and development on frequency synthesis techniques.