Affiliation:
1. National University of Singapore, Singapore
Abstract
Beam steering technology refers to technologies aiming at altering the propagation direction of the main lobe in radiation scenarios. Among the past decades, the beam steering technique has aroused people's attraction in various research directions. Simultaneously, multitudinous emerging realms like radar, biological imaging, wireless communication, and sensing are inseparable from beam steering. In this chapter, the authors have elaborated on the development of beam control technology from the classic mechanical prism to the latest spatiotemporal encoded metasurface. This review first covers geometric dependent methods, including mechanical control, MEMS control, liquid control, and optical control mechanisms, which are on the basis of Snell's law. After that, the phase control methods based on generalized Snell's law such as semiconductor components, electrically tunable materials, phase change materials, MEMS and spatiotemporal metasurfaces are discussed detailly. Finally, the authors summarize the methods of beam control and look forward to future possibilities.