A novel beam-switching printed semicircular antenna design has been proposed to operate at the Terahertz (THz) frequency band. The distinctive feature of the design lies in the use of Graphene to control the radiation characteristics of the antenna. Further, we extend the same idea to explore the applicability of Graphene for isolation of electromagnetic energy with the help of a simple design of a microstrip transmission line with Graphene. The proposed antenna and microstrip line designs have been carried out with an objective of realizing voltage controlled antennas and transmission lines which have lot of potential in various emerging and next generation wireless communication systems such as phased arrays, MIMO systems, sensor networks, etc. © 2016 IEEE.