Analysis On Electromagnetic Field Rules Inside Shielding Enclosure With Penetrated Conductor

In the electromagnetism environment, most of the electrical and electronic systems are equipped with shielding box. In the actual applications, however, for the demand of collection of wire and ventilation, apertures were set on the enclosures. When put a penetrated conductor into the shielding enclosure through the hole, the electromagnetic pulse outside would be directly coupled inside by the penetrated conductor. It seriously influenced the electromagnetic environment in the shielding enclosure.This thesis deeply analyzed the electromagnetic field rules inside shielding enclosure with penetrated conductor of the background of real airborne platform. The models of a shielding enclosure with the penetrated conductor of the conditions of different shapes of enclosure hole, different length and radius of penetrated conductors, different incident angle,different location of observation points and different types of electromagnetic pulses were established to simulate in the electromagnetic software.The results shows that the electric field rules of square aperture and circular aperture with the same area are very similar, however, the shielding effect of the square aperture is a little better than the circular aperture. Compared to the rectangle aperture which has the same area, the coupling energy of square aperture and circular aperture is much larger. Simulation results show that the longer the conductor, the larger the electric field strength is, but the resonant frequencies have not big change. Increasing the radius of penetrated conductor, the electric field strength would be larger. In horizontal polarization way, with increasing incidence angle, the energy of electromagnetic waves decreases. Compared with the normal incidence waves, the field intensity of oblique incident electromagnetic waves is smaller. For the oblique incident waves, different incident angles have little effect on field intensity.Increase distance between observation points and conductor, the coupling ability decreased.According to electromagnetic pulses with different types, the stronger electric field intensityand the narrower the pulse width is, the less the shielding effectiveness is.According to the tests results, the factors of enclosure hole's shape, the length and radius of penetrated conductors, the incident angle, the location of observation points and different types of electromagnetic pulses have an impact on the electromagnetic waves which coupled into the shielding enclosure with a penetrated conductor. The paper will provide the theoretical basis for circuit analysis and design in the boxes with a penetrated conductor, and it has much important and realistic significance.