Tunable Metasurface With Dynamic Amplitude and Phase Control

Tunable metasurfaces are of great potential for the next-generation electromagnetic systems (e.g. beamforming systems due to the capabilities for ultra-fast reconfiguration speed and agile beam programming on the go). The fundamental aspects of tunable metasurfaces laid on their freedom in manipulating the phase and amplitude of the outgoing wavefront. However, the current research heavily focused on the phase manipulation while left the amplitude manipulation capabilities of the metasurfaces barely explored. To unlock the full potential of tunable metasurfaces, in this article, a novel tunable metasurface design with the capability to control both amplitude and phase of transmitted wavefront has been designed, simulated, and characterized experimentally. By incorporating individual phase and amplitude control modules under the guidance of equivalent circuit models, the proposed metasurface achieved the arbitrary phase and amplitude tuning while maintaining reasonably low physical profile. The measurement results of fabricated samples validated the design procedure and fulfilled the flexibility in terms of phase and amplitude tuning, also paved the way towards achieving more powerful dynamic metasurfaces.