Tunable Metasurface With Dynamic Amplitude and Phase Control

Bowen Zheng,Hong Tang,Hang Li,Yunxi Dong,Han Ren,Hualiang Zhang,Clayton Fowler,Mohammad Haerinia,Sensong An

doi:10.1109/access.2021.3099063

Abstract

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.

Highlights

Metasurfaces have been an active research field with extensive attention and innovation due to their capabilities to artificially manipulate the Electromagnetic (EM) wave-front
It is noted that the conventional metasurface design methodology is to implement unit-cells with around 360◦ phase coverage while maintaining relatively high amplitude
Increasing number of resonators can be accomplished by cascading additional layers, attention is needed for carefully designing the layer patterns and adjusting the coupling between the layers to obtain the extended phase coverage

Summary

INTRODUCTION

Metasurfaces have been an active research field with extensive attention and innovation due to their capabilities to artificially manipulate the Electromagnetic (EM) wave-front This property, along with the low-profile nature of metasurfaces, make them perfect candidates for numerous promising applications across a wide range of EM spectrum, from radiofrequency (RF) to optics. It is noted that the conventional metasurface design methodology is to implement unit-cells with around 360◦ phase coverage while maintaining relatively high amplitude. Certain electrically tunable materials or components are employed in the unit-cell design, and the phase responses can be changed dynamically. It is expected that the proposed design will further extend the field of applications of metasurfaces

DESIGN PRINCIPLE AND ANALYSIS

COMPLETE UNIT-CELL RESPONSE

Findings

CONCLUSION