Cross Polarization Discrimination Enhancement of a Dual Linear Polarization Antenna Using Metamaterials

This paper presents a novel approach to enhance the cross polarization discrimination in a dual linear polarization microstrip patch antenna at the frequency of 5.5 GHz. Two different designs of a dual linear polarization antenna using metamaterials are considered. In the first design, microstrip patch antenna is loaded with two pairs of spiral ring resonators, and in the second design, two orthogonal microstrip feed lines are loaded with pairs of split ring resonators. The addition of metamaterial inclusions to the antenna structure allow compensation for an asymmetric current distribution flow on the patch antenna and thus result in symmetrical current distribution on it. This compensation leads to a significant improvement in the cross polarization discrimination in comparison to the conventional dual linear polarized antenna. The simulation shows an improvement of 12 dB for the first design, and 6.6 dB for the second design in cross polarization discrimination as compared to the conventional antenna.