Operating mechanism for RF electromagnetic noise suppression sheets

This paper discusses how the magnetic characteristics of noise suppression sheet (NSS) work on electromagnetic noise based on 3D FEM electromagnetic field simulations and experiments. In low frequencies a NSS shields electromagnetic noise by its high permeability. In this range the interdecoupling ratio reaches 5 dB and the intradecoupling ratio is -2-3 dB which points out that a NSS sometimes has noise enhancement effects. At high frequencies, the NSS suppressed the noise by ferromagnetic resonance losses. In this range the interdecoupling ratio reaches 15 dB and the intradecoupling ratio is about 3 dB.