Characteristics Of Electromagnetic Pulse Coupling Into Irregular Apertures Based On FDTD Method

The rapid development of electronic technology significantly improves the performance of electronic systems, and the electromagnetic environment is more and more complex. Due to the structure characteristics of the aircraft、data display and the signal transmission of the electrical circuit, irregular apertures like annular apertures exist on the electronic cabin, such as aperture of hatch, rivet joint. Electromagnetic pulse can couple into the cavity through the annular aperture, it can influence the performance of electronic system. So the research of electromagnetic pulse coupling with annular aperture becomes more and more important.Based on the aviation science fund project "research of mechanism and protection measures of electromagnetic pulse weapons effect aircraft", the science and technology fund project of Liaoning province "research of protection measures of ultra wideband electromagnetic pulse (UWB) effect the aircraft with composites" and the fund project of Shenyang "research of mechanism and protection measures of electromagnetic pulse effect aircraft" as the research background, this thesis comprehensively studies the characteristics of electromagnetic pulse coupling into the shielded cavity enclosure with annular apertures.Based on the principle of electromagnetic shielding and the finite difference time domain method (FDTD), this thesis deeply analyzed the characteristics of electromagnetic coupling into the cavity with various of annular apertures. It includes, studying the coupling characteristics of electromagnetic pulse into annular aperture with same aperture area but different shape, analyzing the shielding effectiveness of cavity with different shapes of annular aperture; studying the electromagnetic pulse coupling with annular apertures with different area, analyzing the influence of the area size to shielding effect; studying electromagnetic pulse coupling with the rectangular annular aperture with different aspect ratio, analyzing the shielding effect while the aspect ratio of rectangular annular aperture changes when the polarization of electric field is horizontal and vertical:studying electromagnetic pulse with different pulse width coupling with annular aperture, analyzing the impact of the pulse width to the shielding effectiveness; studying the incident pulse with different incident angles coupling with annular aperture when the polarization of electric field is vertical, analyzing the influence of electromagnetic pulse with different incident angles to the shielding effectiveness of annular apertures.The obtained conclusions have important reference significance for electric cabin’s defense against electromagnetic pulse, it has important reference value on how to design annular apertures on the cavity reasonably when the annular aperture is unavoidable.