Mutual coupling reduction in planar Yagi antenna array using bidirectional absorbing metasurface

An effective method for reducing the mutual coupling between the antenna arrays using a bidirectional absorbing metasurface is proposed in this article. This is achieved by embedding the bidirectional absorbing metasurface between the two planar Yagi antennas. The metasurface is mainly composed of 3 × 6 unit cells. Each unit cell includes three-layer metal rings and two-layer dielectric slabs. Since the front and back of the metasurface are completely consistent, a bidirectional absorptivity can reach to 86% or more. Using the proposed metasurface, the mutual coupling at the resonance point can be reduced to about 38 dB. And it has little effect on other performances of the Yagi antennas. Moreover, the proposed metasurface can improve the radiation performance of the antenna array, and make it have a smaller back lobe and a larger front-to-back ratio.