High frequency impedance of amorphous magnetic transmission lines

There are various measurement techniques to determine the magnetoimpedance effect in soft magnetic wires, ribbons, and films, such as LCR meter method, constant AC current method, network analyzer method, and so on. When the measurement is carried out in the frequency of over several hundred MHz, the stray electric/magnetic field effects should be considered with the equivalent circuit parameters (R, L, G, and C), which could be numerically obtained by solving the magneto-dynamics and Maxwell equations. In addition to this, it should be pointed out that the characterization of a magnetic pattern determined by FMR and skin effect is not exact when the geometrical dimension is not sufficiently smaller than electromagnetic wavelength. In this study, the amorphous ribbon patterns and wires were used as signal conductors of transmission lines mounted in the 50-ohm matched measurement system using a network analyzer. And, the impedances and its magnetic field dependencies of the patterns and wires were determined as a function of frequency (0.3 MHz ∼ 3 GHz).