Then according to the emphasis of the design , went deeply into the theory of pll frequency synthesizers widely used , described pll ’ s working principle , structure and several types in detail , and made research and analysis of pll frequency synthesizers ’ phase noise , including the effect of the active loop filter on the phase noise , and give some methods to make improvement as well , such as changing loop filter form , reducing divide number , and increase phase detector frequency , etc . then paper introduced the principle character and phase noise analysis of direct digital frequency synthesizer ( dds ) and injection phase lock circuit , which are also important circuits in the design 论文首先对几十年频率合成器的发展进行概述,而后针对本次设计的重点,对应用较为广泛的锁相频率合成理论进行了深入的探讨,详细介绍了锁相环的工作原理、组成结构和锁相类型,并对锁相频率合成器的相噪特性进行了研究分析,包括有源环路滤波器对于相噪的影响,提出了改善相位噪声的几点措施:改善环路形式、降低分频数、增大鉴相频率等。接着介绍了直接数字频率合成器( dds )和注入锁相电路的原理特点以及相噪分析,它们也是本次设计的重要电路。
Production and processing equipment : bearing production equipment , the ball processing equipment , bearing cleaning equipment , packaging equipment bearings , needle roller processing equipment , light jewelry processing equipment , spherical roller processing equipment , rough processing equipment , double - end grinders , spindle , wheel oilstone and other grinding materials , heat production , high - precision coordinates grinder , and outside grinder , seal marking machine , profilometry , contour dynamic analysis , hardness needle - sorting machine , a round instrument , processing tester , processing meter , dynamic vibration and noise analysis , vibration , noise testing device raceway ultra - precision instrument , roughness measuring instrument , the finish detector , sorting machine , converters and bearing products preservatives , lubricants , cleaning agents , such as processing raw materials 生产及加工设备：轴承生产设备球加工设备轴承清洗设备轴承包装设备滚针加工设备光饰加工设备球面滚子加工设备毛坯加工设备双端面磨床电主轴砂轮油石和其他研磨材料热处理生产高精度坐标磨床内外圆磨床印子打标机轮廓测量仪轮廓动态分析仪硬度针分选机圆度仪加工测试仪加工测量仪振动噪声动态分析仪震动噪声测试装置滚道超精仪粗糙度测量仪光洁度检测仪分选机变频器及轴承产品防腐剂润滑剂清洗剂加工原材料等。
( 3 ) study on the control mechanism of structure noise radiated from rotary machines , we build a common model of rotary machine structure noise analysis relied on the general characters of rotary machines . based on this model , we analyzed various influence factors to structure radiant noise using the union of revolution and numerical calculation method . we found that the joint stiffness between the rotor and the frame is the most sensitive parameter of structure radiant noise by calculating and analyzing 在旋转机械结构噪声控制方面，根据旋转机械的基本特征，建立了旋转机械结构噪声分析的简化模型，基于该模型利用解析与数值计算相结合的方法对结构噪声的各种影响因素进行了分析，通过计算分析发现，转子与机体的连接刚度是机体结构声的最敏感参数，同时各参数对结构噪声的影响具有互补性。
