Multiple-band terahertz metamaterial filter using coupling effect of U-type resonator and two same sizes of metallic split rings

Abstract

This paper presents the multiple-band terahertz metamaterial filter consisting of an U-type resonator surrounded by two same sizes of metallic split rings. Four resonance dips with near zero transmission rates are obtained, of which three dips have narrow line-widths, about one-quarter of the other dip. The physical mechanism of the four resonance dips can be attributed to near field coupling between the three sub-resonators. Influence of structure parameters on the performance of the device is discussed. It is revealed that the frequencies of the four resonance dips can be effectively controlled by adjusting the dimensions of the two surrounded rings, while the number of resonance dips show the significant dependence on the parameters of the U-type resonator. These results indicate that the proposed structure can provide more ideas for multiple-band or broadband metamaterial resonance effects in absorption, filtering, imaging and other related applications.