Patch antenna with polarization agility using ferrimagnetic materials

In this paper we propose the use of the ferrimagnetic compound, yttrium iron garnet (YIG), as a substrate part of a patch antenna operating in Ku band (YIG-Patch). We investigate its influence on the antenna´s polarization properties under the application of an external magnetic field. It is proved that the axial ratio and also the sense and the tilt of the antenna polarization ellipse are strongly influenced by the YIG substrate since they change in respect to the direction and the magnitude of the external magnetic field. Also the presence of this material arises non reciprocal properties in the antenna operation, changing the antenna properties in respect to receiving or transmitting mode.