Metasurface-based wideband, low-profile, and high-gain antenna

摘要

A wideband, low-profile, and high-gain antenna loaded with a dual-layer metasurface is proposed in this study. The metasurface consists of two metallic layers printed on two dielectric layers, in which each metallic layer contains an array of $4 imes 4$4x4 square patch cells. The proposed antenna is fed by an aperture coupled layer under the metasurface. This design makes the antenna work at two different modes with different resonant frequencies close to each other, to enhance the bandwidth. To achieve the best bandwidth performance, a genetic algorithm is adopted to optimise the geometrical parameters of this antenna. This metasurface-based antenna maintains a low profile of $0.09lambda _0$0.09 lambda 0 at 5 GHz, meanwhile yields wideband characteristics for both the impedance and gain bandwidth. The -10 dB impedance bandwidth of the proposed antenna is about 44% (4.08-6.38 GHz) and the 3 dB gain bandwidth reaches 45% (4.16-6.56 GHz) with a peak realised gain of 11.6 dBi. A prototype of the antenna is fabricated and the measured results demonstrate the authors' design.