The microwave absorbing and resonance phenomena of Y-type hexagonal ferrite microwave absorbers

Abstract

The microwave absorbing characteristics and resonance of Y-type hexagonal ferrite–rubber composites were investigated. The complex permeability and permittivity of Ni2−xZnxY ferrite bodies were measured using a network analyzer in the frequency range of 200 MHz–14 GHz. Two types of resonance, the domain wall and the spin rotational resonance, were observed. With a ferrite particle with a diameter of about 1 μm, only spin rotational resonance was observed. The first matching frequency, found in the ferrite–rubber composites, which was higher than that of spin rotational resonance, increased with spin rotational resonance frequency. It was also found that domain wall resonance had no effects on the microwave absorbing characteristics. Based on these findings, it could be concluded that the microwave absorbing characteristics were caused by only one type of resonance, the spin rotational resonance.