Numerical Study of Coupling of ESD Radiation Field to Metallic Cavity with Apertures

In this paper, coupling problem of electromagnetic field radiated by injecting ESD current into thin wire in near field region with a metallic cavity with apertures is studied using FDTD method and the numerical model is established. The computed results show that there is strong coupled field at the vicinity of the aperture in the cavity and the cavity is resonated with the TE 101 mode, TE 201 mode and TE 112 mode as the leading modes. As far as the square aperture, the rectangular aperture and the aperture array with equal areas are concerned, the coupled field through the rectangular aperture with the long side vertical to the thin wire and through the square aperture is much stronger and the coupled field through the rectangular aperture with the long side parallel to the thin wire and through the aperture array is much weaker.