The enhanced electromagnetic shielding effect in the design and simulation of NFC antenna employing optimized NiCuZn ferrite composition with improved magneto-dielectric properties and low-temperature sintering characteristics

In this study, a novel NiCuZn (Ni0.24Cu0.21Zn0.55BixFe2-xO4 (x = 0,0.025, 0.050, 0.075)) ferrite composition (Ni/Zn molar ratio is 24/55) was successfully prepared by the addition of Bi3+ ion for substitution. It is demonstrated that Bi2O3 served as an effective doping agent to reduce the sintering temperature to 900 degrees C and enhanced the high-frequency magneto-dielectric properties. Notably, the maximum permeability is similar to 118 (@ 13.56 MHz) when x = 0.050 with a cut-off frequency of 47 MHz, which is nearly four times higher than that of the unsubstituted sample. In addition, an NFC antenna employing optimized ferrite as an electromagnetic shield sheet was designed and simulated. The results indicated that the chaotic and weakened magnetic field was recovered, and the biased resonant frequency was restored from 31.87 MHz to 13.68 MHz. These findings hold significant scientific importance and practical value in achieving superior electromagnetic shielding performance and miniaturization in NFC system.