Two-peak property in asymmetric left-handed metamaterials

The transmission and reflection properties of left-handed metamaterials (LHMs) with the local asymmetry are investigated at the X -band frequency range in free space. Experimental results show that two transmission peaks and two reflection dips are exhibited in the presence of the asymmetric configuration of split ring resonators (SRRs). Furthermore, the position and intensity of the peaks and dips are significantly dependent on the asymmetry between the SRRs and the wires. In addition, the numerical calculations indicate that two left-handed frequency regions can exist if another configuration of the SRRs is introduced into the LHMs, which is in agreement with the experimental results.