CHARACTERISTICS OF GRID FERRITE ELECTROMAGNETIC-WAVE ABSORBER

A novel ferrite grid electromagnetic wave absorber composed of sintere d ferrite is proposed. Based on the condition that the return loss sho uld be above 20 dB at 30 MHz, its wideband characteristics for suppres sing reflections compared to a single-layer absorber are demonstrated by computer simulation. Calculating the return loss by varying the geo metrical parameters of the ferrite grid, an optimum structure is deter mined which gives the maximum frequency band. In addition, it is found that the return loss of the grid absorber is impaired by an air gap b etween the ferrite and conductor. Moreover, the operating characterist ics of the grid absorber are demonstrated by experimental models.