Nano-antennas Using Single and Double Isolated Graphene for Mid-infrared Applications

In this paper, L-shaped hexagonal patch Nano-Antennas for mid-infrared regions (75-84 THz) using single layer and double isolated layer are proposed. Graphene Nano-Antennas have advantage of frequency tunablity by using graphene chemical potential. Subsequently, a comparative study between the single layer graphene antenna (1G Antenna) and double isolated layer graphene antenna (2G Antenna) is performed. The antenna design and characterization is performed using CST Studio. The proposed antennas are designed based on the conjuncture of graphene plasmonic theory and the transmission line theory. The 1G-Antenna is fed by single graphene ([G]) layer slotted waveguide, i.e., [G]-SiO
₂
-Si and 2G-Antenna is fed by the double isolated graphene ([G]) waveguide, i.e., Si-SiO
₂
-[G]-SiO
₂
-[G]-SiO
₂
-Si respectively. The L-shaped hexagonal patch acts as a radiator element which is responsible for radiation. The comparison are done based on antenna characteristic parameters, i.e., return loss (S
₁₁
), antenna efficiency, directivity, realized gain and radiation patterns according to the graphene chemical potential. The chemical potentials used to study are 0.2 eV, 0.5 eV and 0.8 eV. Based on the simulated results, impedance bandwidth (S
₁₁
≤ -6 dB) decreases in 2G-antenna as compared to 1G-antenna, but there is enormous increase in the antenna efficiency, directivity and realized gain of the 2G-antenna. According to the application, 1G-antenna can be used for the applications requiring larger bandwidth whereas 2G antenna is preferred for better performance.