Effect of the ferrite tiles' gap on ferrite electromagnetic wave absorber

The gap between ferrite tiles degrades the characteristics of ferrite electromagnetic wave absorbers at low frequency. In order to circumvent this, the authors investigated the effect of inserting ferrite powder or rubber ferrite into the gap. Both numerical calculations and experimental studies show that, when the gap is filled with the ferrite powder or the rubber ferrite, the degradation of reflectivity due to the presence of the gap can be reduced compared to the case of the air gap. It is shown that the higher the permeability of the ferrite powder, the less the degradation of the reflectivity becomes. Also, it becomes clear that the degradation of reflectivity due to the air gap in a ferrite grid absorber is less compared to the conventional ferrite tile absorber.