Electromagnetic wave absorption properties of amorphous alloy-ferrite-epoxy composites in quasi-microwave band

Abstract

We report on the electromagnetic wave absorption properties of amorphous alloy-ferrite-epoxy composites with various amorphous alloy fractions in the frequency range from 1 to 5 GHz. We varied the fraction of amorphous alloy in amorphous alloy-ferrite-epoxy composites from 0 to 50 vol. % at a fixed 50 vol.% fraction of epoxy resin polymer. We measured the complex permeability mu and permittivity epsilon of composites by the reflection/transmission technique, and determined the theoretical matching frequency and thickness with maximum reflection loss by plotting the measured mu and epsilon on an impedance matching solution map. The increasing amorphous alloy fraction in amorphous alloy-ferrite-epoxy composites resulted in a larger matching frequency and thinner thickness than those of ferrite-epoxy composite. On the basis of these results, we propose a new, thinner wave absorber, made by optimizing the amorphous fraction and thickness,in amorphous alloy-ferrite-epoxy composites.