Application of Co-based amorphous ribbon to a noise filter and a shielded cable

Abstract

This paper describes the application of a Co-based amorphous alloy ribbon to a common-mode noise filter in the 1 MHz–1 GHz frequency range. Its saturation magnetization, and relative permeability were 6000 G and 1450, respectively. The 10-μm-thick amorphous ribbon exhibits high loss characteristics. The resistance of a 2-mm-diam roll of amorphous ribbon (12.5 mm wide and 30 cm long) increases from 3 Ω at 1 MHz to 50 Ω at 350 MHz. It is confirmed that a filter 1/17th the volume of a conventional (ferrite core) filter exhibits the same noise attenuation. Moreover, the noise emission from a twisted pair cable is greatly reduced without any increase in the cable volume by employing the amorphous ribbon as a shielding material.