A Cylindrical Coordinate System Finite Integral Method For Simulation Of Coupled-cavity High-frequency Characteristics,

Recently, the requirement for the performance of Traveling-Wave Tube (TWT) from military electronic industry and commercial use becomes much higher. TWT plays an important role as high power and wide band microwave generator and microwave amplifier. The higher requirement for TWT is also being promoted by modern satellite communication, space communication, phase array radar and etc., from the aspect of smaller size, longer age, higher reliability and so on.With the development of software technology and the improvement of computer performance, computer simulation technology has been widely used in research of microwave tubes. Assisted by some essential experiments, the Computer Aided Design technology brings some benefits in research and development process, which result in major savings in development time and cost.The major job in this paper is researching the FIT method in the cylinder coordinates, under learning the FIT method and reading relative conferences. Using matlab and FORTRAN language, I write my own program to compute the high frequency characteristic of resonator, wave guide and coupled-cavity. To compare the result with CST or MAFIA proved the correction of method and good precision of this method.At the beginning, the paper simply introduces the relative physic knowledge and some international software had been used widely in the microwave yield, just like CST, MAFIA etc. Secondly, we depict the FIT method learnt from conferences we can look up, give the process of disperse the space. Then we get the problem of Algebra eigenvalue by predigesting the equations formed by FIT method.The paper shows some classical mathematics about solving the eigenvalue of large scale matrix and the methods used in this paper. In solving complex matrix, we use Arpack software. We depict the mathematic method of the software and how to use it.At last, the paper gives some classical microwave structures. By dispersing them and writing FORTRAN program about the FIT method, we get the high frequency characters of them, analyze the results to find the merits and disadvantage of FIT method and find the reasons to solve the problems.