Analyses on the Electromagnetic Shielding Properties of Enclosure with Aperture Array Using Finite-Element Time-Domain Method

In order to investigate the electromagnetic shielding performance of enclosure with aperture array, finite-element time-domain (FETD) formulations which are suitable for inner excitation cases are derived by using variation principle. The lumped resistor is incorporated into FETD code to appropriately consume the system energy and accelerate the process of energy decay. Meanwhile, the delivered power and electric field 3 meters away from the enclosure are calculated and compared with the measurement results or commercial software results and they agree well with each other. Moreover, the analysis on the influence of the various resonant modes and the operation frequency on the shielding performance of the enclosures are conducted based on the frequency-domain results. Finally, the lossy material is placed into enclosures to decrease the quality factor and alleviate resonance. The effectiveness of this method is verified by FETD computational results.