▎ 摘　　要

Antennas are an important part in the microwave and THz systems for the enhancement of the radiation in various application such as medical imaging. Yagi antenna because of end fire radiation, wide bandwidth and high gain are attractive in THz detector, wireless communications and THz medical imaging. Therefore, in this article we have developed a Yagi antenna for 1 THz applications with high gain and in this antenna a graphene loop is added to dipole radiator and with variation in the graphene biasing, reconfigurable characteristic is obtained and the Q-factor is controlled in antenna. The CST microwave studio is used for modeling and simulation with FDTD solution. The antenna's total size is 0.53 lambda x 0.73 lambda for 1 THz with the 1 mu m thickness of the Silicon substrate. Finally, a novel model has been suggested for the implementation of graphene layer in PBG layer and by embedding a graphene pin in PBG layer a Fabry-Perot waveguide has been designed that improves the bandwidth and antenna gain simultaneously. Higher Q-factor, higher bandwidth with high gain pattern are the benefits of the novel structure that are important in THz systems. (C) 2017 Elsevier GmbH. All rights reserved.