A graphene-based multiband antipodal Vivaldi nanoantenna for UWB applications

The design and optimization of an antipodal Vivaldi antenna using graphene material for ultra-wideband applications are described. A frequency-reconfigurable graphene antipodal Vivaldi antenna operating in the terahertz band is designed on a silicon dioxide substrate having thickness h = 3 µm. The antenna is designed and simulated using the finite integration technique in the commercially available Computer Simulation Technology (version 2016) electromagnetic simulation software. Due to its flexibility and hexagonal nature, the graphene-based THz antenna demonstrates multiband resonances. The results for the graphene-based antipodal Vivaldi antenna parameters, such as the return loss, bandwidth, voltage standing wave ratio (VSWR), three-dimensional (3D) and two-dimensional (2D) gain and directivity with co- and cross-polarization, and side-lobe levels, are analyzed. The designed graphene antenna exhibits four resonance bands in the terahertz range, covering the frequency range from 1 to 5 THz. The peak gain can reach 6.48 dBi with directivity of 8.3 dBi at the resonant frequency of 2.31 THz in the operating band from 1.44 to 2.4 THz.