Reconfigurable transmissive metasurface with a combination of scissor and rotation actuators for independently controlling beam scanning and polarization conversion

Polarization conversion and beam scanning metasurfaces are commonly used to reduce polarization mismatch and direct electromagnetic waves in a specific direction to improve the strength of a wireless signal.However,identifying suitable active and mechanically reconfigurable metasurfaces for polarization conversion and beam scanning is a considerable challenge,and the reported metasurfaces have narrow scanning ranges,are expensive,and cannot be independently controlled.In this paper,we propose a reconfigurable transmissive metasurface combined with a scissor and rotation actuator for independently controlling beam scanning and polarization conversion functions.The metasurface is constructed with rotatable unit cells(UCs)that can switch the polarization state between right-handed(RHCP)and left-handed circular polarization(LHCP)by flipping the UCs to reverse their phase variation.Moreover,independent beam scanning is achieved using the scissor actuator to linearly change the distance between the UCs.Numerical and experimental results confirm that the proposed metasurface can perform beam scanning in the range of 28°for both the positive and negative regions of a radiation pattern(RHCP and LHCP beams)at an operational frequency of 10.5 GHz.

Hydrodynamic metasurface for programming electromagnetic beam scanning on the Azimuth and elevation planes

The development of multifunctional and reconfigurable metasurfaces capable of manipulating electromagnetic waves has created new opportunities for various exciting applications.Extensive efforts have been applied to exploiting active metasurfaces with properties that can be controlled by externally controlling active components.However,previous approaches have poor switch isolation,power handling limitations due to nonlinear effects,and complex biasing networks.Therefore,dynamically tunable metasurfaces have become a burgeoning field in many research areas.This paper reports a hydrodynamic metasurface(HMS)that can be programmed to realize electromagnetic beam scanning on the azimuth and elevation planes.The proposed HMS platform incorporates four micropumps,each controlling four metasurface elements via microfluidic channels,built into the HMS base.The proposed platform regulates microfluidic flow through micropumps,causing irregularities in incident wave transmission phase.An HMS was built as a proof of concept,and far-field scanning experiments were performed.Numerical and experimental results verify the feasibility of electromagnetic beam scanning using a hydrodynamic metasurface.This work advances metasurface research,with very high potential for wide-ranging application and a promising route for replacing bulky cascading active components.