Effects of Magneto-Dielectric Ceramics for Small Antenna Application

Hexagonal Ba-ferrites are widely suggested as materials for small antennas. In this paper, the sintering behavior and magneto-electric properties of Ba3Co2-2xMn2xFe24O41 (0.1 <= x <= 0.5) ceramics were investigated for small antenna application. All samples of Ba3Co2-2xMn2xFe24O41 ceramics were prepared by the solid-state reaction method and sintered at 1250 degrees C. From the XRD patterns of the sintered Ba3Co2-2xMn2xFe24O41 ceramics, the Z-type phases were found to be the main phases. The real part of permittivity and permeability of the Ba3Co2-2xMn2xFe24O41 ceramics decreased with frequency. On the other hand, loss tangents of permittivity and permeability tended to behave opposite to real part of permittivity and permeability. The real part of permeability was affected by Mn additions. The real part of permittivity, the loss tangent of permittivity and the real part of permeability, the loss tangent of permeability of Ba3Co0.2Mn0.8Fe24O41 ceramics were 19.774, 0.176 and 15.183, 0.073, respectively, at 510 MHz. In order to investigate the effect of magneto-dielectric ceramics on antenna, PIFA (Planar Inverted F Antenna) was simulated with CST (Computer Simulation Technology). The operating frequency of antenna was decreased without considerable change of bandwidth by using the Ba3Co0.2Mn0.8Fe24O41 ceramics as the carrier.