Graphene-based Yagi-Uda antenna with reconfigurable radiation patterns

Abstract

This paper presents a radiation pattern reconfigurable Yagi-Uda antenna based on graphene operating at terahertz frequencies. The antenna can be reconfigured to change the main beam pattern into two or four different radiation directions. The proposed antenna consists of a driven dipole radiation conductor, parasitic strips and embedded graphene. The hybrid graphene-metal implementation enables the antenna to have dynamic surface conductivity, which can be tuned by changing the chemical potentials. Therefore, the main beam direction, the resonance frequency, and the front-to-back ratio of the proposed antenna can be controlled by tuning the chemical potentials of the graphene embedded in different positions. The proposed two-beam reconfigurable Yagi-Uda antenna can achieve excellent unidirectional symmetrical radiation pattern with the front-to-back ratio of 11.9 dB and the10-dB impedance bandwidth of 15%. The different radiation directivity of the two-beam reconfigurable antenna can be achieved by controlling the chemical potentials of the graphene embedded in the parasitic stubs. The achievable peak gain of the proposed two-beam reconfigurable antenna is about 7.8 dB. Furthermore, we propose a four-beam reconfigurable Yagi-Uda antenna, which has stable reflection-coefficient performance although four main beams in reconfigurable cases point to four totally different directions. The corresponding peak gain, front-to-back ratio, and 10-dB impedance bandwidth of the four-beam reconfigurable antenna are about 6.4 dB, 12 dB, and 10%, respectively. Therefore, this novel design method of reconfigurable antennas is extremely promising for beam-scanning in terahertz and mid-infrared plasmonic devices and systems.

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

“…Nowadays, the graphene is becoming an innovative and attractive material for terahertz and infrared applications in various fields due to its alterable complex conductivity controlled by the chemical potential (P. Y. Chen et al, ; Correas‐Serrano et al, ; X. C. Wang et al, ; Zheng et al, ). Hence, the graphene has a great potential in designing tunable devices such as antennas, filters, and phase shifters at terahertz frequencies (Álvarez et al, ; Fuscaldo et al, ; Wu, Qu, Jiao, & Liu, ; Wu, Qu, Jiao, Liu, & Ghassemlooy, ; Yasir et al, ).…”

“…C. Wang et al, 2015;Zheng et al, 2016). Hence, the graphene has a great potential in designing tunable devices such as antennas, filters, and phase shifters at terahertz frequencies (Álvarez et al, 2017;Fuscaldo et al, 2017;Wu, Qu, Jiao, Liu, & Ghassemlooy, 2016;Yasir et al, 2017).…”

A Review on the Development of Tunable Graphene Nanoantennas for Terahertz Optoelectronic and Plasmonic Applications

“…The critical coupling condition was exploited by changing the voltage across the gate, thus acquiring a high modulation depth up to 100% over a wide bandwidth of 5-7 µm wavelength. Fano antennas based on split ring resonators [177] nanorod gold antennas [139] and optical Yagi-Uda antennas [178] have been theoretically studied and demonstrated for the modulation of antenna characteristics (i.e., directivity, radiation efficiency and beam pattern) by manipulating the chemical potential of graphene upon applying different gate biases. Besides, in some RF and terahertz patch antennas, graphene material is adopted as the photoconductive source the providing dynamic control of modulation with stimulating capabilities [139,179].…”

Applications of Microwave Materials: A Review

“…74 Graphene-based radiation reconfigurable antennas were also reported in literature. 4 Graphene-based ink has been used to design and fabricate a printable dipole antenna for RF identification (RFID) tags at UHF bands. 75 Even though it has some limitations in the interrogation range of tags due to the large resistance of the graphene sheet, it can be considered as an alternative for an expensive silver ink-based antenna.…”

“…Nonetheless, recent developments in technology have realized antennas using graphene and CNTs. 4,5 More advancements and research are required to improve their lesser radiation efficiency. Conventionally, metals are used for electromagnetic shielding due to their good electrical and thermal conductivity.…”