The circuit structure which can transfer one unregulated sinusoidal voltage with high thd into another regulated constant frequency sinusoidal voltage with low thd is constituted of input cycloconverter , high frequency storage transformer , output cycloconverter , input and output filter 该电路结构由输入周波变换器、高频储能式变压器、输出周波变换器以及输入、输出滤波器构成能够将一种不稳定劣质的正弦交流电变换成另一种同频率稳定的优质正弦交流电压。
At last we introduce the realization of all the parts , the problem in the circuit design and the measured data . the results show that the designed system has met the requirement . in this dissertation , direct digital synthesis technology has been used in the phase - locked frequency synthesizer , which can make full use of the characteristics of direct digital synthesis technology such as flexible output wave shape and continuous 本课题将直接数字式合成技术用于锁相频率合成器中,该方法将直接数字合成的特点,如输出波形灵活且相位连续、频率稳定度高、输出频率分辨率高、频率转换速度快、输出相位噪声低、集成度高、功耗低、体积小等与锁相环路的频带宽、工作频率高、频谱质量好等优点有机的结合起来,从而在宽带的条件下实现了比较好的杂散性能和相噪。
The main works and results we have accomplished are as follows : 1 ) red - detuned locking of cooling / trapping laser to the cycling transition of cesium cooling has been accomplished by means of a double - passed acoustic - optical frequency shifting system and the technique of saturated absorption spectroscopy . the short - term residual frequency jitter is less than 350khz ; 2 ) automatic controlling system by computer programs has been established for laser cooling and trapping and cavity qed experiment . the laser and magnetic fields can be controlled by the acoustic - optical modulator and the electronic - controlled logic gate respectively 具体如下： 1 )采用了往返两次通过的声光频移系统结合饱和吸收光谱技术的实验方案，实现了冷却俘获激光频率相对于铯原子冷却循环跃迁的负失谐锁定，短期频率稳定度约在350khz以内，并可方便地调节其负失谐量而无须对后续光路再作调整； 2 )建立了一套基于计算机程序控制的、铯原子激光冷却与俘获实验所需的时序控制系统。
Eddy - current sensor conversion circuit consist amplification circuit , band - pass filter circuit , demodulation circuit , differentiation phase and data sampling circuit . these circuits are used to convert the test signal of eddy - current sensor to discrete signal tend to process . the microprocessor system that formed of dsp chip is used to data fitting of test system , data displaying and data communicating with personal computer , etc . the interference questions of hardware design and the measure of eliminating interference signal in the subject are introduced in the last of this chapter 硬件电路的设计主要分三大部分来实现：激励源电路部分，由分频电路和频率合成电路组成，产生频率稳定的激励信号以确保检测任务的正常进行；传感器变换电路部分，由放大电路、滤波电路、检波电路、鉴相电路和数据采集电路组成，主要将电涡流传感器检测线圈检测到的信号变换成只含有被测信息的离散信号，易于后续电路处理；由dsp芯片构成的微处理系统，主要完成检测系统的数据拟合、显示及与主机通信等功能。
The stability of frequency is the key specification of many modern electronic systems and instruments . with the frequency spectral instruments becoming more and more perfect , the technology of phase noise measurement in frequency domain plays an important role in the measurement of short - term frequency stability 频率稳定度问题是许多现代电子系统和设备的一个关键性技术问题，近来因频谱仪器日臻完善，频域相位噪声的测量技术在短稳测量技术方面已占主要地位。
In our nation , we have worked on the researching of continue radar signal ' s phase noise mesurement equipment in the past . but the equipment for pulse radar signal is still in blank . the object of this dissertation is to study on the denotation of the radar pulse signal ' s phase noise and its measuring method 本文的目的是对射频雷达脉冲信号的频率稳定度的表征和测试设备的研制进行研究，讨论了雷达脉冲信号的测试方法，主要对谱估计法测量射频雷达脉冲信号相位噪声的系统方案进行理论的分析，并对实现过程中技术上的难点重点问题的解决进行论证。
Frequency source is widely used in today ' s electronic equipment and even refered as " a heart " of many electronic systems . the frequency synthesizer with a lot of channels and high frequency stability by means of theory of phase locking has almost been a necessary component in the modern electronic systems such as telecommunication , radar and electronic countermeasure . the phase - locked frequency synthesizer can be generally divided into two kinds : one is digital phase locked frequency synthesizer , the other is analog sampling phase locked frequency synthesizer . compared with the prior , the latter has many merits such as lower phase noise , samller volume , lighter weight and lower power consumption and has a wide foreground in the equipments of microwave band 利用锁相原理来获得波道数目众多、频率稳定度很高的频率合成器，几乎已成为现代通信、雷达和电子对抗等电子系统不可缺少的组成部分。锁相式频率合成器一般分为数字锁相频率合成器和模拟取样锁相频率合成器两类。取样锁相频率合成器与数字锁相频率合成器相比，具有相位噪声低、体积小、重量轻和功耗低等优点，尤其在微波波段的电子设备中，具有广阔的应用前景。
All - solid - state laser is an advantage lamp - house . it has many important applications and potential commercial value in many fields , such as industry , scientific research , military . so it ' s always the research focus of laser field . diode end - pumped solid - state laser has many merits . including high efficiency , long lifetime , high frequency stability , narrow line width , compact configuration , convenient for use et al , which made her a necessity in many high level quantum optics experiments . in this thesis , a series of experiment research was done with regard to blue laser , green laser and infrared laser 激光二极管端面泵浦的固体激光器具有效率高、谱线窄、寿命长、结构简单、使用方便等优点，特别是采用环行谐振腔内加光学单向器构成的单频激光器，由于频率稳定，使其成为许多高水平量子光学实验的主要光源。本论文围绕全固态单频蓝，绿，红外激光器进行了一系列实验研究工作。
In the theoretical calculation , the best approximations algorithm shows its practicability and superiority comparing with the method of least squares . in the practices production , the practicability of the best approximations algorithm can be shown . the frequency stability is about 1ppm in the temperature range : - 20 70 . the frequency stability 在实际生产中最佳一致逼近算法具有实用性,用该算法求取的电阻参数来装配补偿网络,在- 20 - 70窄温度范围内atcxo的频率稳定度为: 1ppm左右; - 40 - 80宽得温度范围内频率温度度在: 2 . 5ppm左右。
Our treatment shows in the raman effect case , mnls solitons , the same as nls solitons , keeps its energy , initial center and initial phase unchanged . however , the raman effect , not the same as nls solitons . reduces its amplitude , widens its width and under the same conditions , the self - frequency shift of mnls soltions is closer to the result of numerical simulation . in the raman effect together with frequency filters case , mnls solitons , the same as nls solitons , keeps initial center and initial phase unchanged and bandwidth - limited frequency filters can make the mean frequency of mnls soltion stand a steady value at the red side of the initial mean frequency , i . e . suppress the self - frequency shift of mnls soltions . and that , the other physical parameters of mnls soltion last stand a steady value . however under the same conditions , the steady value of the mean frequency of mnls soltions is closer to the initial mean frequency and the result of numerical simulation 有所不同的是， raman效应虽然不改变孤子能量，但会引起孤子峰值的下降和宽度变宽，且在同一条件下， mnls孤子微扰理论得到的自频移比nls孤子微扰理论得到的更接近直接数值计算结果。有限带宽的频率滤波也不引起mnls孤子初始中心、初始位相的改变，选取适当的频率滤波器参数值能使孤子的平均频率稳定在初始平均频率的红侧一稳定值，抑制了自频移，而且孤子的各物理量最后都稳定在一稳定值，这些与nls孤子微扰理论都是类似的。有所不同的是，宽度为飞秒量级下， mnls孤子平均频率的稳定值更接近初始平均频率，更接近数值计算结果。
