Abstract
In this paper, an optical smart multibeam cross dipole nano-antenna has been proposed by combining the absorption characteristic of graphene and applying different arrangements of directors. By introducing a cross dipole nano-antenna with two V-shaped coupled elements, the maximum directivity of 8.79 dBi has been obtained for unidirectional radiation pattern. Also, by applying various arrangements of circular sectors as director, different types of radiation pattern such as bi- and quad-directional have been attained with directivities of 8.63 and 8.42 dBi, respectively, at the wavelength of 1550 nm. The maximum absorption power of graphene can be tuned by choosing an appropriate chemical potential. Therefore, the radiation beam of the proposed multibeam cross dipole nano-antenna has been controlled dynamically by applying a monolayer graphene. By choosing a suitable chemical potential of graphene for each arm of the suggested cross dipole nano-antenna without the director, the unidirectional radiation pattern shifts ± 13° at the wavelength of 1550 nm. Also, for the multibeam nano-antenna with different arrangements of directors, the bi- and quad-directional radiation patterns have been smartly modified to uni- and bi-directional ones with the directivities of 10.1 and 9.54 dBi, respectively. It is because of the graphene performance as an absorptive or transparent element for different chemical potentials. This feature helps us to create a multipath wireless link with the capability to control the accessibility of each receiver.
Highlights
In this paper, an optical smart multibeam cross dipole nano-antenna has been proposed by combining the absorption characteristic of graphene and applying different arrangements of directors
Optical multibeam nanoantennas (OMBNAs) have capability to radiate multiple independent beams simultaneously from a single orifice, which leads to the creation of a multi-user wireless access link[4,5]
One contributed approach to design OMBNAs is smart control of the accessibility of each user or receiver that can be realized by utilizing the unique characteristics of graphene to manipulate the radiation beams from the transmitter[6,7,8,9,10,11]
Summary
Displacement of excitation Changing the angle of source from center main lobe direction. To design controllable MBNAs, different methods have been used such as SH effect and displacement of the excitation source from the center in spiral antenna These methods have disadvantages and limitations[11,14,23] like damaging the structure due to the increase of the input intensity, modifying the radiated wavelength, and complex fabrication process. To overcome these restricts, in this paper, by utilizing the monolayer graphene, we have succeeded to suggest the smart OMBNA with different radiation patterns. To confirm the fabrication feasibility of the proposed smart cross dipole nano-antenna it should be mentioned that the vertical aspect ratio of this structure is about 20:1, which some methods such as metal assisted chemical. All important features to confirm the fabrication feasibility of the proposed nanoantenna such as aspect ratio, production of single-layer graphene and silver oxidation have been investigated, which prove that in our simulation we have considered all realistic approaches
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
