Tailoring dual-band electromagnetically induced transparency in planar metamaterials

The transmission characteristics of a planar metamaterial, composed of two finite metal strips (with different length) and one double split-ring resonator, have been numerically and experimentally investigated in this paper. By varying the length of the two strips slightly, this structure can exhibit single-band and dual-band electromagnetically induced transparency (EIT)-like spectral response in microwave region. The dark mode can be excited because of the length difference of the two metal strips, which can lead to a very asymmetric Fano-like resonance or gradually EIT-like profile in transmission. So the dual-band EIT-like physical mechanism is characterized by two bright-dark coupling modes. Our work provides a way to obtain multiple EIT-like effect, and it may achieve potential applications in a variety of fields including filters, sensing, and some other microwave devices. (C) 2015 AIP Publishing LLC.