Dynamically controlling electromagnetic wave with tunable metasurfaces

Dynamic control of electromagnetic (EM) wave propagation (both the amplitude and phase) is essential to many practical applications. The recently developed two dimensional metamaterial - the metasurface, provides more convenient method to manipulate EM wave in a designable way within subwavelength distance. Here we incorporate electrical tunable elements into the metasurface designs to realize dynamic manipulation of EM wave propagation. We will show that the tunable metasurface inspired by the equivalent principle design can provide independent and dynamic tuning for the transmission magnitude and phase. Detailed theoretical analysis, simulation as well as experiment on prototype of tunable metasurfaces will be demonstrated. As an application example, we will also show our recent work on designing a planar Huygens lens that could achieve dynamic focusing through phase control of the metasurface.