Pll Frequency Synthesizer Frequency Technology

Frequency synthesis is one of the key technologies that could achieve high performance index in radar and communication systems. With the development of modern electronic systems, frequency synthesis technology is developing on integration, digitization, broadband, minuteness, high-speed directions, etc.. Frequency synthesis technology get more extensive application in fields.Swallowing pulse pretreatment is frequency-divided technology that could improve speed of frequency-divided extensively. Sigma-Delta modulation frequency-divided technology is fractional-N frequency technology that could create signal with high frequency resolution and low phase noise.This paper research the practical application of swallowing pulse pretreatment technology and Sigma-Delta modulation frequency-divided technology. The paper focuses on the optimizing the algorithmic program, design factual schematic and hardware circuit in based on analysis of its working-theory and working-characteristic, combined with traditional PLL Fractional-N synthesizers structures, and apply it on the spectrum analyzer.The study results and circuit testing indicate that swallowing pulse technology could increase working-frequency and sigma delta modulation technology could improve spurs of fractional-N frequency, content the desire of phase-noise figure and predigest the circuit structure .