Microwave Metalens Antennas for 5G Network

Microwave metalens has been long developed since the 1940s. The metalens is based on the same principle of an optical lens for electromagnetic wave control and implemented using microwave components rather than dielectric materials, for example, for power focusing. Recently, metamaterial-based lens technology has been developed in both optical and microwave bands for flat and low-cost designs. This paper presents the latest progress in the microwave metalens antennas for the 5G network. All metalens are flat and implemented by multilayered metasurfaces. Starting with a flat multiple-beam lens operating at 28 GHz for spatial multiple-input and multiple-output (MIMO), we review the designs of a large-scale metalens for massive MIMO, a three-beam metalens antenna for base stations, and Huygens’ surface-based metalens for low reflection.