Microwave Tube Input And Output Windows And Any Cavities With Finite Element Theory And Cad Technology

Microwave vacuum electron device is one of the indispensable electron devices in microwave or millimeter wave field, especially in microwave communication field owning to its advantages like high gain, high power, high efficiency and wide band. In the recent twenty years, the traditional design that based on analytic theory and experimental research was not enough to improve the performance of microwave tubes, while the CAD technique of microwave tubes which has high accuracy and high performance is the main approach. From 2007, Theory and Computational simulation Lab of UESTC has been doing the research on the design of 3D simulator for microwave electrical devices, which is called Microwave Tube Simulator Suite (MTSS). MTSS consists of five components including MTDE, EOS, HFCS, BWIS, MFS and WS.Under the guidance of MTSS project, based on vector finite element method, this paper firstly did some research on eigen simulation for arbitrary shaped resonant cavity filled with any material. This simulator is one part of HFCS. Then this paper developed the elementary version of WS which can achieve the calculation of S parameters of arbitrary cross-section multi-port network.The main work and innovations are as follows:1. Theory of Finite element method has been deeply studied, and two methods for solution of boundary value problems using finite element method have been grasped. After being familiar with the low order vector basis functions, high order vector basis functions are studied and applied.2. The functional expressions for electric fields of resonant cavity filled with anisotropic material are deduced by Ritz method. Then we use low order vector basis functions to discretize the functional expressions. Finally, the universal program for calculation of eigen frequency, quality factor and electromagnetic distribution of arbitrary shaped resonant cavity filled with any material is realized.3. The weak formulation of boundary value problems of microwave tubes'input/output windows is accomplished, including different boundary conditions imposed. Then high order vector hierarchical basis are applied. Finally, calculation of S parameters of arbitrary cross-section multi-port network is realized.4. To improve the efficiency of analyzing the microwave tubes'windows by finite element method and to use the characteristics of hierarchical vector basis, we apply a p-type multiplicative Schwarz method. Consequently, the large scale sparse matrix can be fast solved.5. By simulating several shaped resonant cavities filled with different materials and comparing with the results of HFSS and analytic results, the accuracy of the program for eigen problems are proved.6. By simulating several examples and comparing with the results of HFSS and CST MWS, the accuracy and the efficiency of the program for S parameters calculation are proved.