The fundamental unit of the high - reliability frequency source is low phase noise reference source , and the sources with optimum frequency stability of reference sources are high reliable crystal oscillator and atomic clock . even the atomic clock itself needs high reliable crystal oscillator 而高稳定的频率源又是以低相噪参考源为基础的，在各种参考源中频率稳定度最好的是高稳定晶体振荡器和原子钟，而原子钟本身也要用到高稳定晶体振荡器。
Finally introduced the method that use adf4113 and provied the real test result of this multi - frequency , low phase noise pll frequency synthesizer with 30mhz working band and 1mhz frequency step . in addition , some method that solved the problem often occurred was introduced 最后给出了由ad公司的电流泵数字鉴频鉴相器adf4113和无源环路滤波器构成的频率合成器的控制方法和实验测试结果，实现了工作带宽30mhz ,频率步进1mhz的多点频、低相噪频率合成器。
In modern microwave and millimeter wave communication systems , the low phase noise frequency sources have the key effects in the systems ’ performance . especially in the national defence , the effects are more obvious . so in this paper , a method to realize the low phase noise x - band frequency source has been proposed , designed , produced and tested 在现代微波、毫米波通信系统中,低相噪频率源对系统性能起着非常关键的作用,特别是在军事国防上,这种关键的作用更加明显,为此在本论文中,就如何实现x波段频率源的低相噪性能,给出了一种设计方法并对其进行了实现。
The goal of this subject is to sum up and exploit our technique how to produce low phase noise wideband vcos , through investigating and studying the basic theory and recent research fruits , combining national condition , and produce our low phase noise wideband vcos . using high q components , such as : coaxial resonator , dielectric resonator , makes bandwidth of vco become narrower , so that recently common wideband vcos generally make inductor and capacitor ( lc ) as resonators , combining varactors with wide range tunable capacitance , and achieve the wideband 本课题旨在通过对低相噪宽带vco的基本原理、国内外在这方面的进展，结合国内的实际情况进行研究，总结和开发出自己的方法，形成自己的理论。并把它运用于实践，以制造出低相噪的宽带vco 。由于加入高q元件，如：同轴谐振器、介质谐振器等，会导致振荡器带宽比较窄，目前的宽带vco一般采用电感电容( lc )作为谐振元件，辅之以大变容范围的变容二极管，达到宽带的目的。
Finally , the production , which is designed and debugged all by myself , c band fine resolution low phase noise frequency synthesizer was introduced by module , including respective schedule , frequency distribution and phase noise experiment results . then whole circuit phase noise result , picture of spectrum with spur were presented , by which above theory was proved , analysis of the result was given , and the existing problem as well as methods to resolve it were motioned 论文最后对自己设计调试的样机c波段小步进低相噪频率合成器进行了分模块介绍,包括各部分的原理框图、频率分配和相噪测试结果,然后给出了整个样机的相噪、杂散频谱测试结果,对上面提到的理论进行验证,并对结果进行了讨论分析,提出了样机现存的一些问题和几点解决措施。
In the first chapter , the class of modern frequency composing techniques and the recent development situations have been introduced . then the advantages and disadvantages of the techniques have been described . at last , based on the techniques mentioned above , a scheme to realize the x - band low phase noise frequency source has been proposed 在第一章引言部分,主要介绍了现代频率合成技术的分类及技术发展近况,并就每一种合成技术的优缺点做了简要的陈述,最后以上述不同合成技术的优缺点为基本指导思想,提出了一种实现x波段低相噪频率源的方案。
Until now , many experts domestic or abroad have researched it deeply and some results have been obtained . purchasing one low phase noise crystal oscillator from foreign countries , the price will be thousands ( even ten thousands ) of yuans . although the price of local low phase noise crystal oscillator is lower , it is still expensive , and the high reliable crystal oscillator with higher specifications can not be produced domestically yet 目前国内外有很多专家对其进行深入的探讨，也取得一些成果，从国外购买一只低相噪晶体振荡器，价格少则几千元，多则几万元，国内的低相噪晶振虽然价格比国外的低，但价格也惊人，况且指标较高的高稳定晶体振荡器还不能生产。
In the course of the low phase noise research , by integrating many aspects , using recent accomplishments , i come up with my method and theory , that by comprehending and controlling subcircuit of oscillator ' s resonator , can let us know exactly their working states . using this method and theory , combining the vco circuit of this subject , i deduce and demonstrate particularly the reason of low frequency oscillation , and come up with the measure of avoiding it . this makes design and producing vcos can avoid the disturbing of low frequency oscillation , and improve the features of vcos . at later process of debugging vco , using this method makes the vco achieves very good working state 在低相噪研究中，综合了各方面的情况，运用了当今低相噪vco的研究成果，并提出了自己的对谐振电路结构进行总体把握，从而准确得知电路的工作状态的思想和理论。运用此方法，在论文中结合本vco电路拓扑结构，详细推导和论证了低频振荡产生的原因，并提出了避免发生低频振荡的措施。使低相噪vco的设计及调试能免于低频振荡的干扰，从而有利于提高vco的各项指标。
This paper mainly introduce the teconology of design modern microwave hopping frequency pll synthesizer with low phase noise . on the foundation of analysis of phase noise performance of pll circuit , i made some reasearch in system shcemes and methods for low phase noise design of microwave hopping frequency pll . some innovative ideas of low phase noise design about pll is presented in this paper 本文主要研究现代微波锁相跳频源低相噪设计技术。在对锁相环噪声性能分析的基础上，对现代微波锁相跳频源多种低相位噪声设计方案进行分析研究。提出了低噪声锁相跳频源设计的一些独道见解。
