Comparative Analysis of Shielding Effectiveness of Cavity Excited by an Internal Source and an External Source in High Frequency Band

Based on the Bethe' small aperture theorem, the analytical models of rectangular cavities excited by internal electric dipole and external electric dipole are established respectively. By comparing the results of the analytical models with CST full-wave simulations in high frequency band, the validity of the analytical models is verified. Finally, by changing the position of the electric dipole and observation point, the difference of shielding effectiveness (SE) of two models is compared. The results show that the SE calculated by the two models is basically the same, but there are still some problems that need to be paid attention to in the actual EMC test so as to fully reflect the shielding effectiveness of the cavity.