Research On Characteristics Of Electromagnetic Coupling With Conductors Penetrated Into Shielding Cavity

Most electronic and electrical equipments have shielding cavities outside to prevent fromexternal electromagnetic interference. However, the circuit inside the shielding cavitiesneeded to connect with the outside world to achieve transmiting signal or connecting thepower lines, and so on. Thus, the external electromagnetic interference will be coupled intothe cavity by the penetrating conductors, having influence on the current of the internal circuitin the cavity, and making the electromagnetic environment inside the cavity very complex. Itis necessary to consider the problems of electromagnetic coupling effects that are caused bythe penetrating conductors to correctly predict the Electromagnetic Compatibility (EMC) ofelectrical and electronic equipment. This thesis is based on the Aviation Science Fund item,Study on Mechanism and Protection Methods of Electromagnetic Pulse Weapons to Aircraft,deeply studing the problems of electromagnetic compatibility relating to the shieldingconductors.The thesis is based on real problems, and mainly does researches on energy changescoupled into electronic equipments inside aircraft equipment cabins with conductorspenetrated. Finite-Difference Time-Domain (FDTD) is used as research method. A3-Dimensional simulation model is established for the following studyings. Firstly, analyzingthe changes of electromagnetic energy coupled into the shielding cavity by penetratingconductor with same length but different radius. Secondly, analyzing the changes ofelectromagnetic energy coupled into the shielding cavity by penetrating conductor with sameradius but different leakage length. Thirdly, discussing the electromagnetic interferencecaused by the number of penetrating conductor. Forthly, studying the changes ofelectromagnetic energy coupled into the shielding cavity by same penetrating conductor withdifferent polarization method of electric field when the incident angle of the electromagneticpulse changes. Fifthly, analyzing the influence of different electromagnetic pulse from thepenetrated conductor. Finally, finding out the coupling effect from electromagnetic field and mechanism of action related to the penetrating conductor, depending on the simulation andresearch.The research data of electromagnetic coupling from the conductor penetrated intoshielded cavity in this thesis has important and realistic significance in reference to theprediction and designing of electromagnetic compatibility in electronic and electricalequipment systems, as well as in reference to the actual terms of improving operationalperformance of the aircraft.