High-Isolation Wide-Angle Scanning Antenna Array Using Heterogeneous Metasurface Elements with Ability of Integrating Millimeter-Wave Array

This manuscript presents a novel heterogeneous antenna array with merits of high isolation and wide-angle scanning operated in Sub-6GHz, which can integrate millimeter-wave (mmW) array in same aperture. Firstly, two kinds of metasurface antennas including square ring metasurface (SRMS) and overlapped metasurface (MS) are proposed, and they are used as heterogeneous elements to construct a scanning array. The overlapped MS significantly minimizes the size of the element. The square ring metasurface antenna exhibits a larger height and high transparency at mmW, in order to provide enough space for mmW antennas. Note that, the different height of the heterogeneous antennas have different phase centers, therefore, an 60° delay microstrip is designed into the feeding network ensuring the phase consistency. To further improve the isolation and scanning performance of the array, some
$\pi$
-shaped decoupling-path and dummy elements are loaded around the array. As result, the array can operate at 3.3-3.6GHz with high isolation that larger than 19.5dB. In addition, it also can achieve a wide-angle scanning performance of
$-56^{\circ}\sim 56^{\circ}$
in the whole band. These results reveal that the proposed heterogeneous array would be potentially applied in mmW/Sub-6GHz aperture-shared arrays.