A Low-Profile Broadband Nonuniform Metasurface Antenna for 5G Terminal Applications

A low-profile broadband metasurface antenna using nonuniform unit cells is proposed for 5G communication systems. The nonuniform metasurface is formed by $4\times 4$ adjustable square patches and fed by an L-shaped coupling probe. By properly optimizing the dimensions of sub patches, four resonances are generated to cover the N77-79 frequency bands (3.3-5.0 GHz) with reflection coefficient of less than −6 dB and total efficiency of better than 70%. Meanwhile, the independent tuning characteristic of the four resonance modes is also analysed. The proposed nonuniform MS antenna has a low profile of $0.028 \lambda_{0}\ \lambda_{0}$ is the free-space wavelength at the center frequency), which is promising to be applied to mobile devices.