Electromagnetic Shielding Effectiveness Analysis of Enclosure Incorporating Frequency Selective Surface

This paper presents the shielding effectiveness (SE) study for enclosure incorporating a newly developed frequency selective surface (FSS) with consideration of the ratio of vent hole array and the oblique wave incidence. Not only is the SE at the center of the enclosure analyzed, but also the global shielding effectiveness (GSE) is evaluated as a complementary approach for more reasonable prediction. Compared to an enclosure commonly shielded by metal with the same vent hole array, the shielding effectiveness of the enclosure with the FSS shield is about 20 dB higher in the frequency range of 23 GHz - 25.5 GHz, which meet the requirements of SE >= 30 dB and BW|SE=30dB > 2 GHz. The results also show that the ratio of vent hole array to one surface of the enclosure has impact on the shielding effectiveness of enclosure. Importantly, the study indicates that FSS technology can be a promising alternative when conventional metallic shielding is limited due to ventilation requirement in the high frequency applications.