Graphene based microstrip antenna for triple and quad band operation at terahertz frequencies

A plasmonic resonator antenna is designed to operate at the lower terahertz (THz) frequency band of 0.5-5 THz. A very thin layer of graphene film about 0.34 nm is employed as the radiating patch. The resonant frequency of the antenna is controlled by tuning the chemical potential of the graphene layer. As the chemical potential of the antenna is varied from 0 eV to 2 eV, we achieve additional resonant modes leading to triple band operation. At a fixed chemical potential of 2 eV, quad band operation is realized for a substrate thickness of 45 mu m. It is inferred that, the operating frequency of the antenna can be varied based on the requirement, by tuning the chemical potential of the graphene layer and by modifying the substrate thickness. For the single band antenna operation, a maximum gain of 2.58 dB and directivity of 2.89 dBi is obtained at 2.58 THz. In the case of triple band operation, a maximum gain of 1.22 dB and directivity of 3.66 dBi is obtained at 4.41 THz. Further, quad band operation is achieved at 1.73 THz, 2.6 THz, 4.01 THz and 4.72 THz, with a maximum gain of 1.61 dB and a directivity of 7.17dBi at 4.72 THz. Further, the effect of chemical potential on the main lobe direction of the radiation pattern, leading to beam steering, is also investigated for the first time.

Automated summary

The plasmonic resonator antenna is capable of operating in triple or even quadruple band modes by adjusting the chemical potential of the graphene layer and modifying the substrate thickness. The antenna demonstrates varying levels of gain and directivity at different frequencies, with the possibility of beam steering due to the effect of chemical potential on the radiation pattern.