Mutual coupling reduction in metamaterial antenna for terahertz application

We investigate in this work an effective approach to reduce mutual coupling between two metamaterial antennas operating at the THz frequency band by incorporating a metasurface designed using an electric inductive capacitive resonator. The metasurface is designed to provide a band stop functionality in the operating bandwidth of the antenna. The proposed method shows that the improvement of mutual coupling is at least 10 dB compared with conventional antennas. Thus, this proposed approach can be utilized to mitigate mutual coupling between antennas in THz application. Moreover, to enhance the antenna performances in terms of return loss, directivity, gain, and radiation efficiency, the antenna is designed with a mushroom structure based on the zeroth-order resonant characteristic of a composite right/left-handed transmission line. The electromagnetic behavior of the antenna is studied and an analytical equivalent-circuit model is also proposed.