Cascaded Graphene Frequency Selective Surface Integrated Tunable Broadband Terahertz Metamaterial Absorber

Rishi Mishra,Ravi Panwar,Arpit Sahu

doi:10.1109/jphot.2019.2900402

Rishi Mishra, Ravi Panwar + Show 1 more

Open Access

https://doi.org/10.1109/jphot.2019.2900402

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Abstract

The quest of novel materials and structures to design an efficient absorber for realizing wave trapping and absorption at terahertz (THz) frequencies is an open topic. But the design of a thin, wideband, and tunable THz absorber is still an arduous job. Hence, in this paper, a hybrid THz metamaterial absorber integrated with a cascaded graphene frequency selective surface (FSS), with ultra-high absorbance over a wide frequency range is designed using an analytical equivalent circuit model. Such an approach provides a feasible way to optimize the device by interrelating the effective electromagnetic and circuit parameters with the unit cell dimensions of FSS. A systematic study and critical analysis over a wide range of device parameters including graphene chemical potential and FSS design variables is demonstrated. A peak dip in reflection coefficient of -30.27 dB is observed at 2.94 THz for an optimal device with a chemical potential (μ c ) of 0.38 eV (μ c1 ), and 0.25 eV (μ c2 ) in the range of 0.1-4.0 THz. The cascaded FSS configuration results in the unique anti-reflection-based absorption phenomena, which is responsible for the achievement of -10 dB absorption bandwidth of 2.34 THz (0.85-3.19 THz). In addition, the frequency-dependent effective permittivity, permeability, and impedance is extracted using reflection data, in order to understand the device physics. Such ultra-thin and broadband absorbing device architecture may confer potential application perspectives in THz sensing, imaging, and detection.

Highlights

Terahertz (THz) technology has emerged as a vital field to discover the possibilities of the future generation technologies
In this paper, a hybrid THz metamaterial absorber integrated with a cascaded graphene frequency selective surface (FSS), with ultra-high absorbance over a wide frequency range is designed using an analytical equivalent circuit model
SA-FSS is used as FSS-I, on the other hand, the square patch FSS (SP-FSS) is utilized as FSS-II

Summary

Introduction

Terahertz (THz) technology has emerged as a vital field to discover the possibilities of the future generation technologies. In the quest of thin and broadband absorber, there is still a probability to further improvement of the absorption properties by employing the concept of multi-layering and cascading graphene FSSs. In this article, a hybrid and tunable multilayered THz-MMA integrating with cascaded graphene FSSs and dielectric layers is designed at THz frequencies using an efficient ECM approach. A hybrid and tunable multilayered THz-MMA integrating with cascaded graphene FSSs and dielectric layers is designed at THz frequencies using an efficient ECM approach Such a THz wave absorbing configuration is superior as compared to the existing single-layers. THz-MMAs in terms of lower thickness, −10 dB absorption bandwidth, and comparable absorption efficiency

Theoretical Background and Design Methodology

Results and Discussion

Conclusion