High Frequency Characteristics of a Magnetic Coaxial Pipe Made of Amorphous Ribbons

The magnetization, impedance, and other characteristics of magnetic coaxial pipe formed by winding amorphous ribbons is reported. Amorphous ribbons, with Cu foil on either edge, were wound into toroids, with leads soldered to the Cu. The impedance of the inner pipe was found to be several hundred times that of the outer pipe when driven at a frequency of 100 kHz, greater than for Permalloy pipes driven at 50 Hz. Such nonuniform radial distributions of permeability and current density may enable applications as unique circuit elements.