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Complex metal cavity shielding effectiveness analysis of antenna coupling characteristics

Author: MaDeJing
Tutor: YinWenYan；PengHongLi
School: Shanghai Jiaotong University
Course: Electromagnetic Field and Microwave Technology
Keywords: Electromagnetic pulse Shielding effectiveness Coupling into Slot Antenna Near - field scattering
CLC: O441.4
Type: Master's thesis
Year: 2010
Downloads: 213
Quote: 1
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Abstract

Electromagnetic pulse as a transient electromagnetic phenomena, with a peak field strength, the rise time is short, wide spectrum, its military and civilian electronic information systems pose a serious threat. Therefore, for the communication network and communication systems to study electromagnetic compatibility and electromagnetic interference problems without delay. Full nonporous and the seam metal shielding box can be effectively achieve electromagnetic pulse protection, but in actual use, in order to connect the signal line, the feeders as well as for the observation and cooling of the window, often require the complete hole, slit metal shielding cavity to open some holes joints, and these the aperture became the external electromagnetic pulse into the channel of the shielding structure, external electromagnetic pulse into the shielded cavity in its internal resonance, and thus greater impact on the normal operation of internal communication system . Currently, rectangular shield cavity wall aperture electromagnetic pulse coupling effect subject to the attention of many researchers, and the lower the degree of concern of the cylindrical shielding cavity. Shielded cylindrical cavity is very common, and the type of its resonant frequency and the resonant frequency and the waveguide mode of the waveguide mode and the rectangular cavity the corresponding shielding effectiveness is very different than the shielding effectiveness of the rectangular cavity, and more complex. Therefore, the shielding effectiveness of the cylindrical shielding structure of great value. Chapter cylindrical shielding cavity wall of a single rectangular slit different slit orientation were analyzed to study the shielding effectiveness by changing the angle of the incident pulse, the polarization state, side slit position and slit width size . And to look at the different shape of the aperture array cylindrical cavity shielding effectiveness, according to the different electromagnetic pulse polarization direction to compare hole array with a rectangular slit array shielding effectiveness. Some useful conclusions on the cylindrical cavity shielding effectiveness. Chapter shielding effectiveness of a combination of large-size structure shielding cavity corresponding analysis. By changing the incident pulse direction and polarization state to examine the the shielding performance characteristics of the large-size shield cavity. Application of simulation software CST calculated size cavity time domain electric field intensity distribution in order to reduce the amount of calculation and improve the calculation accuracy of the shielding effectiveness, this chapter also discusses how to choose the appropriate window function for post-processing of their data, in order to improve the resulting shielding The accuracy of performance results. The fifth chapter analyzes the wireless communication antenna mutual coupling and related properties, and get some performance parameters. First, the scattering matrix network model based on deduced receiving antenna array port from the field to the effective representation of the road port translation, and propose a correction factor beta matrix to more fully consider the characteristics and the load of the antenna near-field coupling effect against each other the impact of decoupling, an amendment to the antenna unit is connected to the load when the output of the output wave voltage. Secondly, the introduction of the correlation coefficient to analyze the correlation between the antennas, and using the correction factor beta matrix correction coefficient formula, so that the antenna connection can reflect the actual receiver, the correlation between the output voltage. Finally, two typical usage scenarios were defined for the second unit helical antenna phone usage, that is, no one head element antenna near-field scattering to examine near-field scattering body with two units helical antenna electromagnetic interaction between the effects of and characteristics of the simulation, analysis and comparison of the correlation between the respective units of the above two scenarios, as well as each unit of output wave voltage.

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CLC: > Mathematical sciences and chemical > Physics > Electromagnetics,electrodynamics > Electricity and Magnetism > Electromagnetic waves and electromagnetic fields
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