A study on miniaturization of a handset antenna utilizing magnetic materials

In this paper, a downsizing technique of handset antennas, by utilizing a magnetic material, is studied at the 2 GHz band. A planar inverted-F antenna (PIFA), which is the popular built-in antenna for handsets, is used here. In our previous study, it was found that magnetic materials have an effect on the antenna performance in the short-pin due to the strong current flow. Firstly, basic characteristics such as input impedance, current distribution and radiation patterns are obtained, and calculated results are compared with measured results. Secondly, change of resonance frequency is examined by arranging various types of magnetic materials. Suitable configuration and arrangement of magnetic materials are also examined. As a result, the possibility of miniaturization is confirmed by utilizing magnetic materials. In the calculation, the electromagnetic simulator HFSS, which can consider magnetic loss, is applied to calculate the VSWR and radiation patterns.