Dielectric Loaded Resonator Finite Element Analysis Method And Its Application

Solving Maxwell's equations for the resonances of a closed cavity is important in understanding and controlling the operation of many devices, including particle accelerators, microwave filters. However, the exact eigenvalues can be obtained only for simple geometries, like as rectangular and cylindrical resonator. For arbitrarily shaped cavities and dielectric-loaded cavities . numerical techniques must be used.The finite element method suits specially in the solution of complex geometry structure and the inhomogeneous medium electromagnetic problem. In the electromagnetic domain, the finite element method has widely used in solving problem such as radiation, scattering, wave guide transmission and resonant cavity problem. This thesis used the finite element analytic method, realized the computation of arbitrary shaped and dielectric-loaded resonant cavity, and gave the program .Then we use this method into the measurement of the dielectric property of the medium which loaded in resonant cavity, and proposed a new method in measuring dielectric property. Finally proved its accuracy through experiments .The principle of this method is: first we can get the resonant frequency and the quality factor through experiment. then use the finite element method to analyse the dielectric loaded resonant cavity ,and get the generalized eigenvalue equation Ax = k02Bx,in matrix B includes the unknownεr′. From the resonant frequence can calculate the wave number k 0,and we can get theεr′which correspond to the resonant frequence through optimize the unknownεr′,then we can get the result. The image part of the complex permittivity can get from the change of quality factor of the resonant cavity.In the experiment,we measured the same material in different size situation, and proved the measurement has good duplication .and also we measured the plasma in even situation and the plasma which is even in axial but has a gauss distribution in radial direction. And the result of the experiment is acceptable.In this thesis the theory research and experimental study of this method had been...