Tunable Terahertz Filter-Integrated Quasi-Yagi Antenna Based on Graphene

Abstract

In this paper, a filter-integrated quasi-Yagi antenna (FIQYA) with quasi-independently tunable passband and front-to-back ratio is proposed by using graphene. The graphene at two ends of the coupled-line ring resonator mainly affects the impedance bandwidth while the front-to-back ratio of radiation patterns is attributed to the graphene-implanted open-circuited director. The bandwidth and front-to-back ratio tunability is accomplished by altering the complex conductivity of graphene controlled by chemical potential. For verification, a 2-THz FIQYA using both perfect electric conductor (PEC) and graphene with two different controllable chemical potentials (μ c1 and μ c2) is simulated. The simulated results show that the maximum tunable impedance bandwidth of the FIQYA is varied from 186 to 235 GHz without affecting the radiation patterns when μ c1 changes from 0 to 0.2 eV. The maximum tunable front-to-back ratio is changed from 11.7 to 15.4 dB while μ c2 is altering from 0 to 0.6 eV, maintaining an acceptable matching bandwidth in all cases.