Performances enhancement of metamaterial loop antenna for terahertz applications

We investigate in this work Terahertz metamaterial resonators which can provide highly sub-wavelength confinement of the electromagnetic field. We demonstrate that a metamaterial behavior can be realized from the proposed terahertz metamaterial called TZ-shaped metamaterial. Moreover, a new structure of wideband loop antenna loaded with negative permeability called meta-material loop antenna is proposed and detailed. Therefore, a negative refractive index, permittivity and permeability are obtained at the resonant frequency for a proposed metamaterial structure. To enhance the antenna performances in terms of return loss, directivity, gain and radiation efficiency, an effective approach based on metasurface cavity is presented. This is achieved by applying a flat metasurface on the top of the antenna based on TZ-shaped metamaterial resonator array which increase the directivity and the gain to be 5.71 dBi and 5.39 dBi respectively and to enhance the radiation efficiency to be 93 %.