| With the trend of high-frequency, high-speed, high-density and high-integrity of electronic equipment, the electromagnetic interference of equipment is becoming more and more serious, especially the crosstalk between lines caused by high density and high level of integration. Therefore, reducing the electromagnetic crosstalk between lines and enhancing electromagnetic shielding of equipment are most important issue.Based on the research of multi-conductor transmission line (MTL) crosstalk theory and shielding effectiveness of transmission line theory, this thesis analyzed the influencing factors of electromagnetic crosstalk between transmission lines and shielding effectiveness of rectangular cavity with apertures. And the factors sensitivity is validated by the orthogonal experimental method. The contribution of the thesis is listed as follows:Firstly, the related theory about electromagnetic interference and electromagnetic shielding is studied in this thesis based on the theory of orthogonal experiment. It includes the basic theory of orthogonal test design, MTL equation, finite difference time domain method (FDTD) and shielding effectiveness of transmission line. It provides a theoretical basis for the design of orthogonal experiment.Secondly, the optimization and analysis about MTL electromagnetic crosstalk are carried out in this thesis. Based on the analysis of MTL, this thesis proposes two experimental indexes (near end crosstalk and far end crosstalk) and gives five influence factors of crosstalk. The orthogonal experiment for the selected influence factors are performed to confirm the main factor of influencing the crosstalk between lines. The optimal parameters combination is confirmed with the comprehensive balance analysis method. The electromagnetic crosstalk between transmission lines is improved obviously comparing the test results before and after optimization.Then, the optimization and analysis about electromagnetic shielding effectiveness of the perforated rectangular cavity is carried out. This thesis gives four influence factors for single rectangular cavity shielding effectiveness and confirms the range of every influence factor in the condition of the cavity size is 300mm×100mm×300mm. In order to improve the shielding effectiveness, get the order of influencing factors for the electric shielding effectiveness and magnetic shielding effectiveness, and confirm the optimal level of influencing factors, the orthogonal experiment is carried out. And the shielding effectiveness of rectangular cavity is improved obviously comparing the test results before and after optimization.Finally, the research findings of this thesis is summarized. It is confirmed that the research contents of this thesis can be used to guide the engineering practice comparing the results of optimization. |
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