Broadband metamaterial antenna using folded parasitic patch

In this paper, the broadband metamaterial antenna utilizing zeroth-order resonance (ZOR) mode and TM₀₁₀ mode is presented. Employing the folded parasitic patch, the frequency of TM₀₁₀ mode can simply be down-shifted to the frequency of ZOR mode without changing the size of the antenna. Therefore, the metamaterial patch antenna operates at two modes. As a result, the 10 dB fractional bandwidth of an antenna is measured to be 12.0% and it shows good agreement with the simulated result. Finally, the excellent radiation efficiencies are measured to be 78%~95% in the whole band.