The Electromagnetic Properties Research Of Ion Substituted M-Type Hexagonal Ferrite For The Antenna Applications

As the rapid development of high frequency and miniaturization in mobile communications equipment, it is urgent to look for the requirement of antenna miniaturization. The traditional antenna structure on miniaturization has developed to the stage of "bottleneck". The size of the antenna rely on the influence of the transmission spectrum. The size of antennas in very high frequency(VHF: 30-300 MHz) is lager(~ 40 cm), which seriously limits the development in miniaturization and portability. Therefore, the demand of new material in the antenna miniaturization is also increasing. The Co- Ti ion substituted barium M-type of hexagonal ferrite in VHF section has a stable magnetic permeability and dielectric constant, and magnetic loss and dielectric loss also can be adjusted low. So it has the prospect of antenna miniaturization material application.This paper is the research on Co-Ti ion substituted barium M-type hexagonal ferrite. We studied the infiuence on the amount of Co-Ti ions to phase structure, morphology, static magnetic characteristics and the initial permeability of M-type hexagonal ferrite. The studies have shown that the amount is 1.2, the ferrites show the best soft magnetic properties. And then the research is mainly focused on the low temperature sintering and microwave properties of Co-Ti ion substituted barium M-type hexagonal ferrite. By adding flux bismuth oxide, as well as the regulation of the amount of adding bismuth oxide, we found bismuth oxide content is 5wt%, its magnetic permeability and dielectric constant value in 10-300 MHz range is almost equal(~ 12), and magnetic loss and dielectric loss at very high frequency range is also very low.With HFSS simulation analysis, the hexagonal ferrites were applied to the microstrip antenna base material, we found that the ferrite materials can meet the requirements of the application of microstrip antenna. Compared with the traditional dielectric materials, ferrite materials not only reduced the size of the antenna, and its bandwidth, impedance matching characteristics and scope of radiation to ascend. These results indicate that the Co-Ti ion substituted barium M-type hexagonal ferrite is a kind of very good preparation antenna substrate materials.