Analysis of the typical characteristics of aperture coupling for aircraft under electromagnetic environments

The electromagnetic field outside an aircraft can usually be coupled into its interior regions through the aperture and gap on the fuselage, changing the electromagnetic environment inside the cabin and even seriously interfering with onboard electronic and electrical equipment. In this paper, utilizing a scale model of the fuselage compartment, the coupled electric fields (CEF) formed inside the cabin by the external electromagnetic field through the window and crack between the door and its frame have been studied. The corresponding shielding effectiveness (SE) at each position in the cabin also has been derived. More specifically, the influences of the dimensions of gaps around the door and the shape, size, quantity of the window and spacing between windows on the distribution of CEF and SE inside the cabin have been investigated and analyzed. The simulated results show that the CEF and SE distribution inside the cabin is related to the model structure and frequency of external radiation electromagnetic field. Moreover, the CEF values at certain positions in the cabin may be even greater than that of the incident wave. The SE of the aircraft can be effectively improved by rationally placing the electronic equipment inside the cabin based on the simulation results.