Research On Effects Of Deformations On The Transmission Characteristics Of Triangle Ridge Waveguide

Since Cohn obtained ridge waveguide with the advantages of long cutoff wavelength,wide single-mode bandwidth, and low characteristic impedance through transverse resonance method, ridge waveguide is widely used in microwave engineering, radar systems, electromagnetic compatibility, and communication engineering. Analysis of transmission characteristics of the ridge waveguide provides theoretical basis and reference data in the application of microwave communication project. It is also the basic theory of microwave transmission line design.The finite element method, a highly efficient numerical method, is based on variation theory. The basic principle of this method is that the mathematical model with complex boundary conditions is discretized into multiple simple sub-domains and the model is solved by obtaining numerical solution of these sub-domains.This dissertation is based on the triangle ridge waveguide, including triangle single- and double-ridged waveguide. Considering that deformation of the ridge waveguide devices may occur in the process of manufacturing, the influence of displacement distortion, distortion under stress and combined deformation on cutoff wavelength, single-mode bandwidth,attenuation constant, power-handling capability, and characteristic impedance of the triangle ridge waveguide are researched. The research method is to construct models and obtain the cutoff characteristics in ANSYS, and then these data are input into MATLAB in order that other characteristics are computed and the graphs are drawn. The core contents of this dissertation include two parts, namely, the influence of deformation on the transmission characteristics of triangle ridge waveguide filled with homogeneous dielectric material and the influence of deformation on the transmission characteristics of triangle ridge waveguide partially filled with homogeneous dielectric material.Research results demonstrate that, firstly, for the displacement deformation, cutoff wavelength, attenuation constant and characteristic impedance of the triangle ridge waveguide are increased by increasing deformation, while single-mode bandwidth and power-handling capability of the triangle ridge waveguide are decreased by increasing deformation. Secondly,for the unilateral deformation and bilateral deformation, attenuation constant and characteristic impedance are increased by increasing deformation, while cutoff wavelength, singlemode bandwidth and power-handling capability are decreased by increasing deformation.Thirdly, for the bottom deformation, cutoff wavelength, single-mode bandwidth and attenuation constant are increased by increasing deformation, while power-handling capability and characteristic impedance are decreased by increasing deformation. The bottom deformation also has a larger influence on each characteristics parameter than the other threedeformations, which is primarily caused by the field distribution of the ridge waveguide concentrating on the central part of the ridge. Finally, for the combined deformation,displacement unilateral deformation has a smaller influence on the cutoff wavelength and single-mode bandwidth of triangle ridge waveguide, whereas the trilateral deformation and displacement bottom deformation have a larger influence on the attenuation constant,power-handling capability and characteristic impedance of triangle ridge waveguide.Therefore, the bottom deformation should be avoided in the practical engineering application.The obtained data will provide theoretical foundation and data reference for the design and optimization of ridge waveguide. The conclusion can be used to determine the change in transmission characteristics of deformed ridge waveguide, and it provides theoretical foundation for the application of ridge waveguide.