Open AccessFrequency tunable graphene metamaterial reflectarray for terahertz applications
Author(s) -
ZainudDeen Saber H.,
Mabrouk Ahmed M.,
Malhat Hend A.
Publication year - 2018
Publication title -
the journal of engineering
Language(s) - English
Resource type - Journals
ISSN - 2051-3305
DOI - 10.1049/joe.2018.5016
Subject(s) - metamaterial , materials science , graphene , terahertz radiation , split ring resonator , optoelectronics , resonator , optics , phase (matter) , antenna (radio) , radiation , reflection coefficient , frequency band , metamaterial absorber , tunable metamaterials , telecommunications , physics , computer science , nanotechnology , quantum mechanics
A graphene‐based metamaterial (GMM) reflectarray antenna with frequency tunable radiation characteristics has been investigated in this study. The unit‐cell element consists of graphene split‐ring‐resonator (SRR) with two gaps printed on a grounded SiO 2 substrate. The electrical properties of the metamaterial unit‐cell have been determined at different graphene chemical potentials and different SRR gaps using the waveguide simulator. The metamaterial unit‐cell element introduces negative ɛ r and μ r over a wide frequency band starting from 390 to 550 GHz. A reflectarray unit‐cell element based on the GMM is designed at different frequencies. The phase compensation of the reflected waves is achieved by changing the SRR gap width. Reflection coefficient phase variations for 0°–301° with a variable slope are obtained for different graphene conductivities. Three different 13 × 13 GMM reflectarrays are designed and analysed at different graphene chemical potentials. A maximum gain of 22.6, 19, and 21.5 dB with side lobe level (SLL) is 11.31/9.15, 10.98/5.31, and 7.31/8.45 dB in an E/H‐plane for the reflectarray arrangements (I), (II) and (III), respectively. An averaging phase curve is calculated to construct a single structure GMM reflectarray with frequency tunable radiation characteristics. A maximum gain of 21.8 ± 1 dB with improved SLL of 13 dB was achieved.