Wire Media - Ferrite Substrate for Patch Antenna Miniaturization

We discuss antenna miniaturization using new metamaterials, combining advantages of artificial dielectric and natural magnetic materials. It is known that the reduction of an antenna size using dielectric substrate causes the decrease of the antenna bandwidth. At the same time, the inclusion of magnetic materials into substrate allows to increase the bandwidth. It stimulates attempts to use artificial magnetics inserted into substrates of patch antennas. However, such a way did not bring considerable successes due to some reasons, mainly due to difficulties to achieve simultaneously a noticeable real part and small imaginary part of permeability in a sufficient frequency range. In this paper we propose to use as a substrate a magnetized ferrite filled with wire media whose role is to reduce the effective permittivity of the substrate. Our estimations, based on the transmission line theory, show that the radiation quality factor can be strongly minimized using the proposed substrate