【摘要】：本文從實際需要出發(fā),以如何設計低相位噪聲晶體振蕩器為研究課題,分析了晶體振蕩器相位噪聲產(chǎn)生的機理,并探尋了一種新的仿真方法,通過該仿真方法指導的晶體振蕩器的設計,達到了很好的相位噪聲指標。本文的工作有:1)深入分析了反饋式振蕩器的工作原理,分別得出了振蕩器振蕩的相位穩(wěn)定和幅值穩(wěn)定條件,然后以復數(shù)振蕩方程為計算工具,著重分析了巴特勒振蕩電路的工作原理。之后確定了本課題的諧振器選用SC切型,選取巴特勒共基串聯(lián)振蕩電路作為主振電路。隨后基于經(jīng)典Leeson模型,重點分析了巴特勒振蕩器的相位噪聲,并利用無源網(wǎng)絡推導出了LQ的表達式,通過MATLAB計算得出LQ和2C的關系曲線,得出在兩者之間合理折中可以降低相位噪聲的結(jié)論,為接下來的課題設計奠定理論基礎。2)介紹了ADS仿真軟件以及諧波平衡仿真基礎,首先給出了使用ADS理想模型進行仿真的振蕩器相位噪聲曲線,通過跟理論相位噪聲譜結(jié)構(gòu)的比較分析,得出仿真出現(xiàn)錯誤的原因是由于沒有考慮非線性器件噪聲的影響,于是探尋了一種新的仿真方法,即建立晶體管的非線性模型,再次進行仿真后,得到了考慮非線性器件影響之后的相位噪聲仿真曲線,并且通過與理論相位噪聲譜結(jié)構(gòu)的比較證實了該仿真方法的正確性,對接下來振蕩器的設計提供了指導。3)對晶體振蕩電路的噪聲來源進行挖掘,在分析的基礎上給出了低噪聲晶振的設計原則,設計了頻率為80MHz的低相位噪聲晶體振蕩器。課題研究的最后,制作出80MHz低相位噪聲晶體振蕩器的樣機,然后使用Agilent E5052B信號源分析儀實際測試了該晶體振蕩器的相位噪聲,測得相位噪聲水平為:-140dBc/Hz@100Hz,符合設計要求,并通過與國際上相近頻率范圍內(nèi)振蕩器相位噪聲指標的比較,論證了該方法的價值,完成了本課程的設計。
[Abstract]:In this paper, the mechanism of phase noise generation of low phase noise crystal oscillator is analyzed, and a new simulation method is explored, which is based on the practical needs and how to design a low phase noise crystal oscillator. The design of the crystal oscillator guided by the simulation method achieves a good phase noise index. In this paper, the working principle of the feedback oscillator is deeply analyzed, and the phase stability and amplitude stability conditions of the oscillator are obtained, respectively. Then the complex oscillation equation is used as the calculation tool. The working principle of Butler oscillating circuit is analyzed emphatically. Then the SC tangent type of resonator and Butler common base series oscillator circuit are selected as the main oscillator circuit. Based on the classical Leeson model, the phase noise of Butler oscillator is analyzed, and the expression of LQ is derived by using passive network. The relation curve between LQ and 2C is calculated by MATLAB. The conclusion that the phase noise can be reduced by a reasonable compromise between the two is obtained. The theoretical foundation for the next project design is established. (2) the ADS simulation software and the harmonic balance simulation foundation are introduced. First, the phase noise curve of the oscillator simulated by ADS ideal model is given. By comparing with the theoretical phase noise spectrum structure, it is concluded that the reason of the error in the simulation is that the influence of nonlinear device noise is not taken into account. A new simulation method, that is, the nonlinear model of transistors is established, and the phase noise simulation curve considering the influence of nonlinear devices is obtained after the simulation is done again. The correctness of the simulation method is verified by comparing with the theoretical phase noise spectrum structure, and the design of the oscillator is guided by .3) the noise source of the crystal oscillation circuit is excavated. Based on the analysis, the design principle of low noise crystal oscillator is given, and the low phase noise crystal oscillator with frequency of 80MHz is designed. Finally, a prototype of 80MHz low phase noise crystal oscillator is made, and the phase noise of the crystal oscillator is tested by using Agilent E5052B signal source analyzer. The phase noise level is measured to be: -140 dBc / Hzr 100 Hz, which meets the design requirements. The value of this method is proved by comparing with the phase noise index of oscillator in the similar frequency range of the world, and the design of this course is completed.
【學位授予單位】：電子科技大學
【學位級別】：碩士
【學位授予年份】：2015
【分類號】：TN752

【共引文獻】

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1 徐衛(wèi)林;無線射頻通信片上系統(tǒng)的壓控振蕩器與電源管理的研究[D];武漢大學;2011年

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1 朱成輝;用于條紋相機的同步掃描電路設計[D];西安電子科技大學;2014年

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本文編號：2245961