Shielding effectiveness measurements on enclosures with various apertures by both mode-tuned reverberation chamber and GTEM cell methodologies

The shielding effectiveness (SE) measurements on enclosures with various apertures by both reverberation chamber (RC) and GTEM cell (GC) methodologies are presented. Furthermore, computer simulation through commercial software (CST) is used to compare with the experimental data. Our results show that the SE of the rectangular enclosure with five different apertures from RC is usually larger than those from GC. The reason for this is related to the random polarization and various angles of incidence within the RC, where various polarization and incident angles are averagely and randomly coupled into the EUT. However, as for the GC, the normal incidence with vertical polarization usually corresponds to the worse case, which leads to the worse SE of the enclosure. Surprisingly, an abnormal phenomenon is found from the enclosure with nine periodic rectangles. According to Charles F Bunting's work, moreover, it is still reasonable because many rectangular apertures on the enclosure may lead to a fact that the coupled energy of oblique incidence may be larger than that of normal incidence. Finally, we obtain conclusions about the use of two experimental methodologies in SE measurement. © 2008, Electromagnetics Academy.