Mid-Infrared Reflect-Array Antenna With Beam Switching Enabled by Continuous Graphene Layer

Henry Giddens,Liang Yang,Yang Hao,Jing Tian

doi:10.1109/lpt.2018.2814684

Henry Giddens, Liang Yang + Show 2 more

Open Access

https://doi.org/10.1109/lpt.2018.2814684

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Abstract

Tunable graphene conductivity can enable dynamic control of the reflection characteristics of near-resonant electromagnetic structures. In this letter, a mid-infrared reflect-array antenna with binary beam switching is presented. The proposed structure consists of a uniform graphene monolayer patterned with an aperiodic array of near-resonant metallic split-ring resonators. By controlling the chemical potential of the continuous graphene layer through electrostatic biasing, the reflection phase and amplitude of the split-ring resonator is controlled, providing binary beam switching capability to the reflect-array.

Highlights

I N RECENT years, the mid-infrared (IR) and THz frequency bands have gained the interest of a number of industries for applications such as wireless communications, imaging and remote sensing [1], [2]
One way to achieve beam steering of electromagnetic (EM) radiation is through a reflective surface with a spatial phase distribution, otherwise known as a reflect-array antenna
This allows us to design an array with two chemical potential dependent, constant, phase gradient profiles that are required in order achieve the binary beam switching effect

Summary

INTRODUCTION

I N RECENT years, the mid-infrared (IR) and THz frequency bands have gained the interest of a number of industries for applications such as wireless communications, imaging and remote sensing [1], [2]. One way to achieve beam steering of electromagnetic (EM) radiation is through a reflective surface with a spatial phase distribution, otherwise known as a reflect-array antenna These devices have been investigated by the research community for applications at frequencies spanning microwaves to optics [3]–[5]. By tuning the chemical potential of graphene resonators, the reflect-array is able to steer an incident light beam towards different directions This design requires nano-scale patterning of a large number of graphene nano-ribbons, which is more difficult to achieve in practice compared with a single continuous graphene sheet. With the fabrication advantage of continuous graphene, researchers have proposed to directly load unit cells of gold rod antennas [14] These designs are more suited for amplitude and phase modulation of the reflected light uniformly across the reflect-array, rather than beam steering through a phasegradient surface. By tuning the chemical potential of graphene sheet through electrostatic biasing, binary-state beam switching of the far-field radiation is obtained

UNIT CELL DESIGN

BEAM SWITCHING

FURTHER DISCUSSION

CONCLUSION