Design and Numerical Analysis of Tri-band Terahertz Metamaterial

A simple and compact triple-band polarization-independent metamaterial absorber is presented at Terahertz (THz) frequency range. The proposed planar structure composed of two crosses which are mutually rotated for 90 degrees. The unit cell of the absorber is composed of a top metallic patch and a ground metal plane, both separated by means of a polyimide dielectric substrate having the thickness of 0.125mm. This structure resonates at 0.3072 THz, 0.36 THz and 0.4728THz with absorptivity of 92%, 97.6%, and 98% respectively. The high electromagnetic absorption and polarization-independent behavior were obtained by the overlapped two crosses within the structure. Our design is a step in advance of the formerly proposed terahertz absorbers for its smooth design approach which eliminates the fabrication issue. The field distributions had been studied for a better understanding of the absorption mechanism. The Triple-band absorber is a promising candidate as absorbing elements in technical and medical packages due to its multiband absorption and polarization insensitivity.