Performance Enhancement of Patch Antenna in Terahertz Region Using Graphene

Abstract

Background: Graphene offers a new approach to THz communications due to its ability to support the propagation of SPP waves in the THz frequency band, and that desirable feature allows miniaturization of antenna size to micrometer scale without operating the antenna at very high resonant frequencies. The aims of this paper are to introduce readers to the conventional metallic square patch antenna fed by microstrip line with quarter wave transformer is redesigned with graphene as patch on silicon dioxide substrate with optimum height of 1.8 µm and permittivity of εr = 4. The conductivity model of graphene is formulated with finite thickness of the patch in order to investigate the effect of substrate properties and patch dimensions on the performance of microstrip fed square patch antenna in terahertz (THz) regime. Methods: Research and online content associated to graphene as patch conductor is reviewed, and the proposed antenna geometry is designed and optimized in finite element method (FEM) based high frequency simulator (HFSS) software. Graphene as patch conductor material on SiO2 as substrate put forward good optical distinguish making it easy to make out the graphene layer. Results: The use of graphene patch as conducting material for antenna, due to extraordinary electromagnetic properties and functionalities would exhibit enormous potential to enhance gain, return loss, radiation efficiency, radiated power and bandwidth. The paper shows enrichment of patch antenna in terahertz region using graphene to achieve return loss of -27.57 dB with reasonably good decibel gain at 13 THz. Much improved impedance bandwidth of 12.3% is achieved in the band of operation from 12.2 - 13.8 THz. Conclusion: To explore the feasibility of using nano-antennas to meet the challenges of providing various miniaturized portable wireless communication devices for more flexible applications communicating at faster rates. It is apparent that graphene composite is an effective alternative to metal for the antenna structure offering simplicity in design. It is evident from the various results in terms of return loss, gain, radiation efficiency and bandwidth that the graphene based antenna realizes better characteristic as compared to metallic antenna. Keywords: Graphene, FEM, nano-antenna, SPP, terahertz.