Application of Fe-based nanocrystalline ribbon to a noise filter and a shielded cable

The paper describes the application of Fe-based nanocrystalline alloy ribbon to a common-mode noise filter and a shielded cable in the 10 MHz-1 GHz frequency range. A 0.01-mm-thick Fe-based nanocrystalline alloy ribbon exhibited high permeability and high impedance characteristics. The resistance of a 5.5-mm-diameter roll of Fe-nanocrystalline ribbon (12.5 mm wide and 6 cm long) increased from 1.0 Ω at 1 MHz to 5.1 Ω at 700 MHz. We confirmed that this filter exhibited the same noise attenuation as a conventional filter (ferrite core) but with 1/20th its volume. Moreover, the noise emission from a twisted pair cable is greatly reduced without any increase in the cable volume by employing the nanocrystalline ribbon as a shielding material.