Surface Electromagnetic Performance Analysis of a Graphene-Based Terahertz Sensor Using a Novel Spectroscopy Technique

Abstract

In this paper, a novel terahertz (THz) spectroscopy technique and a new graphene-based sensor is proposed.The proposed sensor consists of a graphene-based metasurface (MS) that operates in reflection mode over a broad range of frequency band (0.2 − 6 THz) and can detect relative permittivity of up to 4 with a resolution of 0.1 and a thickness ranging from 5 m to 600 m with a resolution of 0.5 m. To the best of author's knowledge, such a THz sensor with such capabilities has not been reported yet. Additionally, an equivalent circuit of the novel unit cell is derived and compared with two conventional grooved structures to showcase the superiority of the proposed unit cell. The proposed spectroscopy technique utilizes some unique spectral features of a broadband reflection wave including Accumulated Spectral power (ASP) and Averaged Group Delay (AGD), which are independent to resonance frequencies and can operate over a broad range of the spectrum. ASP and AGD can be combined to analyse the magnitude and phase of the reflection diagram as a coherent technique for sensing purposes. This enables the capability to distinguish between different analytes with high precision which, to the best of author's knowledge, has been accomplished for the first time.

Terahertz Channel Propagation Phenomena, Measurement Techniques and Modeling for 6G Wireless Communication Applications: A Survey, Open Challenges and Future Research Directions

“…THz-TDS [127], [131], as depicted by Fig. 7(a), is a channel sounding technique where material properties are being probed by ultra-short light pulses.…”

Engineered Electromagnetic Metasurfaces in Wireless Communications: Applications, Research Frontiers and Future Directions

“…The phenomenon of completely absorbing the impinging THz waves on metasurfaces can be obtained by manipulation of both the electric and magnetic properties. THz metasurface absorbers can greatly improve the energy management in wireless networks and facilitate the design of THz sensors with high sensitivity [9]. A further SEM-based technology which can be considered for future wireless communications systems is RIS as outlined in Section III.A.…”

A metasurface-based electronically steerable compact antenna system with reconfigurable artificial magnetic conductor reflector elements

“…Metamaterials have been known to exhibit such beyond nature capabilities and have been used in various applications ranging from microwave to optical frequencies covering a wide range of implementations from metantennas, reflectarrays, radar cross-section reduction, terahertz sensors to optical super lenses. 14 , 15 , 16 , 17 , 18 , 19 , 20 To further understand how metamaterials can be used to realize AMCs, let us consider an electromagnetic wave traveling through a medium with intrinsic impedance . When this wave impinges on another medium with a different intrinsic impedance , it encounters discontinuity resulting in reflections.…”