U-slot patch antenna with low RCS based on a metaferrite substrate

Metamaterial ferrites or metaferrites are artificial magnetic materials which mimic the properties of ferrites at a certain frequency operation. Antenna engineers are therefore able to design and create artificial substrates which replicate the electrical properties of ferrites without actually using any in the construction. This is advantageous as ferrites can offer performance improvements to microstrip antennas, such as size reduction and wideband impedance matching. In this paper, a metaferrite substrate designed by the use of a genetic algorithm is presented. The metaferrite was optimized in order to obtain the magnetic responses at 9GHz, for its use as the substrate of a microstrip antenna. As an example, a U-slot patch antenna based on the metaferrite is demonstrated, which can achieve stable radiation and 14 dB radar cross section (RCS) reduction performance in the measurement.