Application of Fe-based nanocrystalline ribbon as a noise filter

The paper describes the application of Fe-based nanocrystalline ribbon to a common-mode noise filter in the 1 MHz/spl sim/1 GHz frequency range. A 10 /spl mu/m thick Fe-based amorphous ribbon was converted into an Fe-based nanocrystalline ribbon by annealing it at 550/spl deg/C for 10 min. The ribbon exhibited high permeability and high impedance characteristics when it was annealed in a transverse magnetic field. The resistance of a 5 mm diameter roll of Fe-nanocrystalline ribbon (12.5 mm wide and 6 cm long) increased from 3 /spl Omega/ at 1 MHz to 10 /spl Omega/ at 1 GHz. We confirmed that this filter exhibited the same noise attenuation as a conventional filter (ferrite core) but with 1/33rd its volume.