Composite Electromagnetic Wave Absorber Made of Ni-Zn Ferrite Particles Dispersed and Isolated in an SiO₂ Medium

Abstract:

In order to design a ferrite absorber that can be used at frequencies of several GHz, the frequency dependences of the relative complex permeability μ_r^*, the relative complex permittivity ε_r^*, and return loss were investigated for a composite made of Ni-Zn ferrite and SiO₂. When ferrite particles were dispersed and isolated in an SiO₂ medium, the frequency dependence of μ_r^* was different from that for a composite made of SiO₂ particles dispersed and isolated in the ferrite medium. Moreover, when ferrite particles were isolated and a suitable mixture ratio of ferrite and SiO₂ was selected, the return loss was less than −20 dB at frequencies of several GHz. The dispersion states of ferrite and SiO₂ particles are thus important factors to design an absorber, and improvement in the absorption characteristics of the ferrite tile which is used as a practical absorber could be achieved using a composite made of Ni-Zn ferrite particles dispersed and isolated in an SiO₂ medium.

• Periodical: Key Engineering Materials (Volume 485)
• Pages: 229-232
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.485.229
• Online since: July 2011
• Authors: Kenji Sakai, Yang Guan, Yuuki Sato, Shinzo Yoshikado
• Keywords: Composite, Electromagnetic Wave Absorber, Isolated Model, Ni-Zn Ferrite, Relative Complex Permeability, SiO₂

References

[1] Y. Naito and K. Suetake: IEEE Trans. Microwave Theory Tech. Vol. 19 (1971), p.65.

[2] K. Lichtenecker and K. Rother: Phys. Z Vol. 32, (1931), p.255.

[3] K. Sakai et al.: Key Eng. Mater. Vol. 320 (2006), p.193.