Shielding Effectiveness of Soft Ferrite Materials

Bernd DEUTSCHMANN, Gunter WINKLER, TU Graz

 

Are ferrite absorption sheets useful to reduce the electromagnetic emission?

Today Electromagnetic Interference (EMI) has become more and more important. The higher integration density of ICs together with higher operating frequencies and higher power densities is leading to higher emissions of disturbances. Because of the reduction in size also the coupling of disturbances inside of an electronic system is causing more and more problems. The sources of disturbances and common countermeasures are described.

A special focus of this presentation is put on the use of ferrite absorber materials  for the reduction of electromagnetic emissions. It is investigated how far the materials are useful to suppress radiated electromagnetic fields (near field and far field) and also if they can help to reduce conducted noise. Different measurement techniques and their measurement results are presented and discussed.