On the shielding effectiveness of enclosures for transient near-field sources
Purpose - The purpose of this paper is to introduce and investigate a useful and practicable definition of the shielding effectiveness (SE) of enclosures for transient near-field sources. Design/methodology/approach - The transient SE is defined as the ratio of electromagnetic energies absorbed by an unshielded and by a shielded vanishingly small load. That ratio can be found analytically by means of a suitable spherical-multipole approach. The SE can be reduced to easily measurable values of frequency-domain electric and magnetic fields. Findings - Suitable factors are introduced which depend on the frequency and on the distance between the dipole source and the measurement point inside the shield. The proposed definition has been analytically evaluated and validated for the case of a cylindrical shield. Originality/value - The paper extends a recently proposed definition of the transient SE for plane-wave incidence to the case of a dipole near-field source.
magnetic fields electromagnetic fields compatibility methods