State-of-the-Art Millimeter-Wave Beam Steering Antennas for Beyond 5G and 6G Networks: A comprehensive review

This is a review article discussing the latest developments in beam steering antennas at millimeter-wave (mm-wave) frequencies for beyond 5G and 6G networks. This article classifies all the beam steering techniques described in the literature in four categories, namely, phased arrays, quasi-optical systems, leaky wave antennas (LWAs), and metasurfaces. An overview of the four classifications is presented, with a detailed comparison outlining the state of the art and limitations of different technologies.