PERMEABILITY MEASUREMENT IN THE GHZ RANGE FOR SOFT-MAGNETIC FILM USING THE M C/M INDUCTANCE-LINE/

This work reports a new technique for measuring permeability of magnet ic alloy films above 1 GHz by using an inductance-line, which has a ma gnetic alloy films(M)/conductor(C)/magnetic alloy films(M) stacked str ucture and is installed in a microstrip circuit. The imaginary part of the relative permeability mu(r)'' was estimated from the magnetic abs orption in the M/C/M inductance-line, by analyzing its transmission ch aracteristics. The Kramers-Kronig relation was used for the transforma tion from mu(r)'' to the real part mu(r)'. Complex relative permeabili ty was measured in the 1 MHz-20 GHz frequency range for NiFe/SiO2, CoZ rNb/SiO2 and CoFe/SiO2 multilayer films. The mu(r) - f characteristics , static relative permeability mu(r)' (0) and ferromagnetic resonance frequency f(k) values were confirmed to agree with those obtained by t he conventional M/C/M technique and by calculation.