Near-zone to far-zone transform in FDTD analysis for the leakage from aperture arrays [enclosure shielding]

Aperture arrays for airflow in enclosures can become the coupling path of electromagnetic interference (EMI) from the interior to the external environment. In this paper, the relation of the leakage and aperture area is investigated numerically and experimentally in term of SE (shielding effect). In practice, the number of apertures is large and the size of a single aperture is very small compared to the wavelength. In this work, FDTD (finite-difference time-domain) modeling deals with the different number and size of apertures. To save computation effort, the pulse source and FFT is accordingly employed. The near-zone to far-zone transform is improved by integrating the numerical method and the analytical formulation. The model building approach is proved effective by a comparison of SE experimentally and numerically.