Synthesis and Characterization of (Ba2Zn2Fe12O22)0.5(MgFe2O4)0.5 Composite for High Frequency Antenna Application

Abstract

There has been huge demand of composite ferrites for antenna and microwave absorber [1, 2]. Hexagonal ferrite and spinel ferrite composites have been reported to show the tuning of magneto-dielectric properties and proposed for high-frequency antenna application [1]. The Y-type hexagonal ferrite; Ba2Zn2Fe12O22 (Zn2Y) and MgFe2O4 (MgF) spinel ferrite composite; (Zn2Y)0.5(MgF)0.5 was prepared by one step co-precipitation route. Precursor powders were calcined at 1100oC/4h for phase formation. Pellets and toroids were fabricated using calcined powder and sintered at 1220oC/4h. Phase composition was evaluated by XRD analysis (Fig.1(a)). The FESEM microstructure of sintered specimen (inset of Fig. 1(a)) shows development of plate like Zn2Y ferrite grains and cubic MgF spinel ferrite grains together. Permittivity (εr) of ~14, permeability (μr) of ~29, dielectric loss (tan ) of ~0.21, magnetic loss (tan μ) of ~0.08 were found at 100 MHz frequency. Miniaturization factor (n=μ)0.5) of 20.14 and characteristic impedance (Zi=Z0(μ/)0.5) of 1.4 were evaluated at 100 MHz. Magneto-dielectric resonator antenna was simulated based on the dielectric and magnetic properties of (Zn2Y)0.5(MgF)0.5 ferrite composite using ANSYS HFSS and found return loss (S(1,1))~ -40 and voltage standing wave ratio (VSWR) ~1 at 8 GHz which is suitable for high frequency antenna application.