Dependence of Electromagnetic Wave Absorption on Ferrite Particle Size in Sheet-Type Absorbers

In this study, we have investigated the effect of particle size of Mn-Zn ferrite on the electromagnetic wave absorption properties in sheet-type absorbers. With increasing average particle size, the matching frequency shift toward lower frequency, and the absorption ability of the electromagnetic wave at each matching frequency decreased. However, the absorption ability increased with increasing average size of particles at 0.8 GHz and 1.8 GHz. We suggest that a sheet-type ferrite absorber with large Mn-Zn ferrite particles is useful for mobile phones.