Fabrication of RF Magnetic Shielding Plate Having the Polarization Characteristics

As one of the basic areas of research for the improvement of the electromagnetic environment, the present paper has developed the carbon plate having the polarization characteristics. To exhibit the polarization characteristics in the far field region, it has formed the slit on the surface of carbon plate. The value of the RF magnetic shielding degree SD_HH for holding the slit of a carbon plate horizontally, in the frequency region of 1 MHz to 1 GHz, increased with frequency, and had the value of 58 dB at 1 GHz. Also shown that the value of SD_HP for holding the slit perpendicularly indicated about 10 dB in the frequency region of 1 MHz to 1 GHz. Namely, the difference of shielding degrees of the carbon plate to direction of slit is indicated the polarization characteristics. Experimental results revealed several characteristics of the slitting carbon plate that include the influences of polarization characteristics on the slit length L and slit number N. In the present paper, it is improved the polarization characteristics by the superposition of slitting ferrite plate over a slitting carbon plate, termed a compound plate. In addition, important criteria are discussed for the design of an effective RF magnetic shielding plate having polarization characteristics.