The Research On Cesium Beam Frequency Standard Electronics Servo System

Time is the most important and essential physical element.High stability time benchmark is consumingly required in many fields such as aerospace industry,astronomical observation,scientific research,transportation industry,military application,etc.Cesium beam frequency standard as one of the universal high stability frequency standard,has been widly used,which having the good precision and stability.The miniature magnetic state-selection cesium beam frequency standard becomes mature commercial products for several years abroad.But until now,in domestic market,we have no mature commercial products to substitute the imported products,so the research on miniature magnetic state-selection cesium beam frequency standard becomes very significance for our country to break through the high-tech embargo and improve the ability of scientific research.This dissertation systematic describes the physical foundation and structure of the cesium beam frequency standard,especially devoted to the servo electronics system.Digital PLL and DDS frequency synthesizer which are parts of the servo electronics system are described in detail in the dissertation.The servo electronics test product was made.The joint test of the servo system and the cesium tube was successful.The main works of this paper were presented as follows:1?Firstly this dissertation describes the physical foundation of the cesium beam frequency standard.Based on the structure of the atom,explains the theoretical basis that why the atom frequency standard should be presently the most accurate frequency standard.This dissertation also depicts the structure of atom beam resonance device which is the theory prototype of the cesium beam tube.And then describes the structure and working principle of the cesium beam tube of magnetic state-selection cesium beam frequency standard.2?This paper proposes the scheme design of the whole system,describes the detailed design and working principle of every module in the servo electronics system.3?The next,this paper detailed describes the design of middle frequency phase-lock-loop.Based on the discussion of PLL theory,the dissertation explains the design foundation and scheme in making digital middle frequency phase-lock-loop using chip PE3236.4?Then,the dissertation also detailed describes the design of DDS frequency synthesizer,which is the other important module of the servo electronics system.From the working principle of DDS,the application of chip AD9852 to the detailed scheme of this module,the dissertation describes specifically.Based on the result of the joint test with the cesium tube,the design of the servo electronics system been proved crrecetly.The performance of the whole system in the close loop working state also been proved meet the requirement.