RF magnetic shielding effects of a compound plate constructed from bincho-charcoal and ferrite plates

With rapid development in the field of information technology, there has been increased interest for electromagnetic shielding in the radio frequency (RF) region. An excellent RF magnetic shielding material can be realized by the use of bincho-charcoal, a high quality charcoal found in Japan, due to its very large value of relative permittivity in the RF region. The present paper has improved the RF magnetic shielding characteristics of a bincho-charcoal plate to realize a broadband frequency by the superposition of a ferrite plate over the bincho-charcoal plate. This configuration is termed the compound plate. The RF magnetic shielding effects of the compound plate have been examined, including the characteristics of the RF magnetic effect against both the frequency and the RF magnetic power. In addition, RF electric shielding effects have been examined as functions of the frequency and the RF electric power.