Intelligent metasurface with frequency recognition for adaptive manipulation of electromagnetic wave

Hai Peng Wang,Shi Jin,He Li,Shi Yu Wang,Tie Jun Cui,Si Jia Li,Shu Yue Dong,Qian Ma,Kai Nan Qi,Jia Lin Shen,Yun Bo Li

doi:10.1515/nanoph-2021-0799

Hai Peng Wang, Shi Jin + Show 9 more

Open Access

https://doi.org/10.1515/nanoph-2021-0799

Copy DOI

Abstract

Abstract Due to the strong ability of recognizing electromagnetic (EM) environment and adaptively control of EM waves, the intelligent metasurfaces have received great attention recently. However, the intelligent metasurface with frequency recognition for adaptive manipulation of the EM waves has not been studied. Here, we propose a frequency-recognition intelligent metasurface to precisely control the spatial EM waves under the agile frequencies with the help of a real-time radio-frequency sensor and an adaptive feedback control system. An active meta-atom is presented to reach 2 bit phase coding and 1 bit amplitude coding capacities to control the amplitude and phase independently. Experimental results demonstrate that the metasurface can recognize different frequency of the incoming wave with very high resolution, and can adaptively realize the self-defined multiple frequency agilities to manipulate the reflected EM waves without any human participation. As example, the intelligent metasurface with frequency recognition can adaptively operate wave absorption at 5.36 GHz, reflection to normal direction at 5.38 GHz, deflection to −30° at 5.40 GHz, random diffusion at 5.42 GHz, and deflection to +33° at 5.44 GHz by detecting the incoming frequency at the resolution of 0.02 GHz.

Highlights

Metasurfaces have attracted a great deal of attention owing to their advantages of low loss, easy fabrication, low profile and multi-versatility [1–8]
The metasurface should be designed with the capability of recognizable and adaptive, which means that it can sense the frequency of incoming waves and automatically feedback and adjust to meet the functional design requirements
The adopted micro-controller unit (MCU) is a low-cost system with the clock speed of 72 MHz, in which a code is preloaded to control the 62-channel digital-to-analog converters (DACs) generating biasing voltages according to the captured frequency information through the data acquisition card with the sampling rate of 1 kHz

Summary

Introduction

Metasurfaces have attracted a great deal of attention owing to their advantages of low loss, easy fabrication, low profile and multi-versatility [1–8]. They are defined as the twodimensional (2D) structures at surfaces or interfaces with different geometries and distributed functional arrangements. Owing to the simultaneous manipulations of EM waves in both the space and frequency domains, the space-time-coding digital metasurfaces [20] and time-domain digital coding metasurfaces [21, 22] have attracted growing interests and provided promising applications in multi-user new-architecture wireless communications, cognitive radar, and related areas. With the rapid development of various tuning strategies, a great deal of tunable or reconfigurable metasurfaces have been proposed to achieve in dynamic manipulation of EM waves to solve the drawback of static functionality that depending on their fixed geometrical parameters in the passive metasurfaces [23].

Methods

Results

Conclusion