Gain enhancement of a slot antenna with a metamaterial superstrate structure

This paper presents a technique to increase the gain of a slot antenna with the help of a single layer metamaterial (MTM) superstrate. The gain enhancement is achieved using the zero-index property of the metamaterial. The increased broadside gain for the proposed antenna is 6.42dB more in comparison to that of the reference slot antenna. The overall thickness of the MTM loaded antenna is 0.15λ0, where λ0 is the free-space wavelength at the resonance frequency of the antenna. A high efficiency of about 96.20% is obtained for proposed antenna. The loading of the metamaterial superstrate produces minimal effect on the cross polarization performance of the slot antenna.