Design of a Graphene‐Based Tunable Frequency Selective Surface and Its Application for Variable Radiation Pattern of a Dipole at Terahertz

Abstract

In this paper, a frequency selective surface (FSS) with tunable bandstop performance by integrating graphene is discussed. The graphene implanted in the circular FSS unit makes the transmission and reflection bands of the proposed FSS tunable owing to its alterable complex conductivity controlled by the chemical potential. The transmission zero of the proposed FSS performing as a reflection plane happens at the frequency from 1.65 THz to 2.19 THz when the chemical potentials of graphene change from 0 eV to 1 eV. Moreover, reconfigurable radiation pattern of a traditional dipole antenna is accomplished loaded with the proposed FSS by altering the complex conductivity of graphene. The dipole has a directional radiation pattern with enhanced directivity at 2.1 THz by adding the proposed FSS with μc = 0.8 eV. However, the omnidirectional radiation pattern is maintained by changing the value of chemical potential to 0 eV while the FSS is nearly transparent. Therefore, a radiation diversity property could be achieved by controlling the chemical potential of graphene loaded in FSS.

A graphene‐based tunable miniaturized‐element frequency selective surface in terahertz band and its application in high‐isolation multiple‐input multiple‐output system

“…Besides, the center resonance frequency of the stop band shows an obvious blue shift from 1.76 to 2.56 THz when increasing the chemical potential of the graphene from 0 to 0.5 eV, which is due to the fact that the conductivity of the graphene is increased with the increase of the chemical potential. Similar blue shift phenomena have been reported in other graphene‐based reconfigurable devices . Figure B shows the corresponding reflection coefficients.…”

“…Fortunately, graphene is a potential candidate to replace the varactor diode owning to its tunable surface conductivity within the THz frequency range. Recently, some graphene‐based THz FSSs have been reported . However, the dimensions of these devices is still too large for future highly integrated circuits.…”

Simulation and optimization of tuneable microstrip patch antenna for fifth-generation applications based on graphene

“…Here, the first approach in the antenna design is to use same for all graphene strips. In order to achieve practical values for the ON and OFF surface impedances ( and ), the following equations are used [18][19][20]. ,…”

Graphene based microstrip patch antenna on photonic crystal substrate for 5G application

“…Goyal and Vishwakarma (Goyal and Kumar Vishwakarma, 2018) investigated the effect of graphene's chemical potential on return loss and resonant frequency of the antenna; Mojtaba and Carey (Dashti and David Carey, 2018) show a graphene antenna with dynamic conductivity to produce a surface impedance microstrip antenna with a bandwidth of hundreds of GHz. In Qu et al (2018) proposed a frequencyselective surface (FSS) with tunable band stop performance.…”