Characterization of graphene for performance enhancement of patch antenna in THz region

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 thickness of 1.8 mu m and permittivity of epsilon(r)=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 width on the performance of microstrip fed square patch antenna in THz regime. The resonant frequency is reduced as the graphene becomes narrower. The proposed antenna geometry is designed and well optimized with reasonably good decibel gain and directivity at 13 THz. The antenna provides improved impedance bandwidth of 12.3% in the band of operation from 12.2 to 13.8 THz. It is revealed that metallic patch can be conveniently substituted by graphene patch metal for the antenna structure hence offering simplicity in design particularly at THz regime. The radiation characteristics including radiation efficiency and absorption cross section show significant improvement for graphene based patch antenna. The simulation and design optimization has been performed using High Frequency Simulator Software (HFSS), which is a commercially available electromagnetic simulator based on finite element method technique. (C) 2015 Elsevier GmbH. All rights reserved.