Decoupling Wideband Antenna Array by Employing Metasurface

Abstract

Wideband decoupling is an arduous task, as antenna performances, including impedance matching, radiation pattern, gain, etc., should all be considered in a broad band. In this paper, a hybrid metasurface is presented to alleviate mutual coupling of wideband dual-layer coupled microstrip $H -$plane patch antenna array. Dual-band response is excited by introducing multi-layer mixed split ring resonant (SRR) element, then $\mathrm{a}7 \times2$ metasurface is inserted between the array elements, the edge-to-edge space of which is 11mm $( 0. 18 \lambda_{0})$, enabling the center-to-center one to be $0. 37 \lambda_{0}$. Unlike most decoupling examples arranging metasurface above the antenna array, the proposed metasurface brings no change to the array profile. Results indicate that the proposed metasurface can suppress the mutual coupling below the level of -20 dB in the band of 4.26--5.50GHz (25.4%). Meanwhile, the radiation patterns are modified and the gains are improved. Thus, the proposed metasurface is potential in the application in the multi-element antenna arrays.