Broadband Ni $_{\rm x}$Zn $_{0.8 - {\rm x}}$Cu $_{0.2}$Fe $_{2}$O $_{4}$ Electromagnetic Absorber for 1 GHz Application

Ni$_{\rm x}$ Zn$_{0.8 - {\rm x}}$Cu$_{0.2}$ Fe$_{2}$ O$_{4}$ ferrites with various composition $({\rm x} = 0.45 \hbox{--} 0.79)$ were synthesized by the coprecipitation method for broadband and electromagnetic absorbing characteristics. Saturation magnetization decreased as the Ni content increased, while coercivity was elevated. It was found that calculated reflection loss and fractional bandwidth (FBW) changed with the matching thickness and chemical composition of the ferrite. Minimum reflection loss (RL) of ${-}$47.05 dB and FBW of 105% were observed at 1 GHz for Ni$_{0.45}$Zn$_{0.35}$Cu$_{0.2}$Fe$_{2}$O$_{4}$ , which are competitive to those of conventional ferrite and ferrite rubber composite absorbers.