Control of magnetic loss profile for RF noise suppression sheets

The ideal frequency profile of magnetic loss μ" for the magnetic composite sheets to be used as high performance RF noise suppressors is a steep rise of at the critical frequency followed by gradual decay of 1/f. We testify that the μ" profile can be improved by combining the multiple elemental dispersion of μ" and applying magnetic field. Furthermore, patterning of the sheets into a stripe array works effectively to reduce the strength of the external field because of enhancement of the shape anisotropy. Consequently μ" profile closer to that of the ideal RF noise suppressor is obtained.