Design And Research Of Micro-Multi-Stage Depressed Collector

Microwave Power Module(MPM)as an important electronic device plays an important role in modern defense military and economic society.Traveling-wave tube(TWT)is the core part in MPM,and the Multi-stage Depressed Collector(MDC)of TWT owns the largest outer diameter.The miniaturization/micromation and high efficiency of MDC are of great significance for the development of efficient TWT,the reduction of MPM dimension and the improvement of MPM efficiency.In this thesis,the basic principle of MDC is introduced,and the foreward designing methods of a MDC is proposed.This thesis briefly introduces the calculation principle of MDC,and designs the electrical performance of MDC of TWT based on the practical application background of a research project.According to the design results,simulations and calculations were carried out by using software MTSS2015.This paper introduces the influence of the size of components and thermal conductivity of various materials on the temperature distribution and thermal margin of MDC in TWT,as well as the effect of various parameters,and how to provide reference for the design and optimization of the heat dissipation structure of the MDC.In order to realize the application of microengineering,we use three-stage MDC to verify whether the designed MDC can also meet the requirements of engineering application.Thermal analysis of the designed micro-MDC is needed.According to the design requirements of MDC and the results of electrical performance design,Ansys thermal analysis was carried out for MDC and its application environment MPM.In this thesis,the process of fabricating TWT and MDC were introduced.In order to reduce the secondary reflux of electrons,surface treatment of collector electrodes is needed.In order to decrease the secondary electron emission and improve the efficiency of MDC,the study of collector electrode modification was conducted.Based on our designed data,the MDCs and tubes were fabricated and some parameters were got by hot measurement.All parameters are accord with the expected requirement.The novelty of the thesis is to propose a foreword designing method for MDC,and to realize the micro-MDC.With the efficiency of 15% in TWT,the recovery efficiency up to 70% in MDC was realized,and the outer diameter of the MDC is only 11.5 mm.In addition,the results also verified verify the accuracy and reliability of MTSS2015 suite package.