Study On Effects Of Deformations On The Transmission Characteristics Of Ridge Waveguides

Since the introduction of the waveguides by Cohn in 1947, they have received considerable attention, and research on them has continued steadily. Compare to the normal rectangular waveguide, ridge waveguide has the character of broader bandwidth, smaller dimension, lower equivalent characteristic impedance, etc. Because of these merits, it is used more and more widely in micro-wave and millimeter-wave devices. In early research of ridge waveguide, they mainly research single-ridge waveguide and double-ridge waveguide, then, the recent research is more complicated structure of ridge waveguide, for example, trapezoidal-ridge waveguide, antipodal-ridge waveguide, etc.. In order to meet some requirements in modern microwave transmit systems, it needs to research some new waveguides with especial sections. Then in production and practice, owing to some reasons, such as production, assembly, use, and so on, which can bring about deformations of ridge waveguide. And it is helpful to reinforce practice use to analyze deformations of ridge waveguide to influence of transmission characteristic.There are four chapters in this paper. In first chapter, development of ridge waveguide, and the importance in practice of this paper are introduced; In second chapter, there are waveguide theory, the transmission characteristics of the normal rectangular waveguide; In third chapter, the finite element method employed in this paper is introduced; In fourth chapter, the transmission characteristics of many kinds of ridge waveguide in different deformations is obtained by employing the finite element method. On the basis of existing data, choosing geometry dimension of ridge waveguide in the better transmission characteristics, the calculation results are compared with the data that published on foreign and home authoritative issues, comparison between the literature data and the computed results in this paper can be found that the results in this paper agree well with the literature data, which prove that the method and the program are effective and accurate enough.The paper uses the finite element PDE toolbox in the Matlab environment to obtain the transmission characteristics of the waveguide in displacement deformation and different deformation under stress, and works out the normalized cutoff wavelength,single-mode bandwidth and he relevant field pattern. Numerical results indicate that the change of the transmission characteristics of the waveguide in displacement deformation is smaller; the change of the transmission characteristics of the waveguide in deformation under stress in both sides is the most and the transmission characteristics change bad; the transmission characteristics of the waveguide in deformation under stress in underside change well. The ridge waveguide devices can be designed and used based on these parameters.