Performance of Graphene Plasmonic Antenna in Comparison with Their Counterparts for Low-Terahertz Applications Sasmita Dash 1 & Amalendu Patnaik 1 Received: 25 January 2018 /Accepted: 25 April 2018 /Published online: 9 May 2018 # Springer Science+Business Media, LLC, part of Springer Nature 2018 Abstract Graphene has attracted great interest for antenna applications because of its two-dimensional nature and superior electronic properties. Low losses, strong confinement, and high tunability properties of surface plasmon make this material as one of the suited material for terahertz applications. In this paper, we have investigated the surface plasmon polariton properties and plasmonic resonance of the graphene dipole antenna at low-terahertz frequency range and compared its radiation performance with that of carbon nanotube and copper, in order to find the suitability of these materials for THz antenna designing. Surface conductivity and surface impedance of graphene, carbon nanotube, and copper at terahertz band have been studied. The performances of these antennas are analyzed, and it was found that graphene plasmonic antenna better suits for making THz antennas. Keywords Terahertz . Antenna . SPP . Graphene . Carbon nanotube . Copper Introduction ACUTE shortage of spectrum in the lower frequency range and benefit of using higher frequencies led the researchers to think of using beyond gigahertz frequency and towards terahertz (THz). The THz (= 10 12 Hz) radiation refers to elec- tromagnetic radiation in 0.1–10 THz range. In recent years, THz technology has gained more research attention which can be marked from the application of this in fields like defense, medical, earth and space science, material characterization, communication, sensing and imaging, etc., [1–7]. Presently, the focus is more towards the lower THz range because of the availability of the sources in this range [8–10]. A thorough literature survey reveals the use of metals, carbon nanotube (CNT), and graphene as the materials for antenna design in low-THz frequency. Copper is the most widely used metal in radio frequency and microwave frequency range. But, the design of THz copper antenna faces many challenges starting from the technological limitation of micro fabrication up to the requirement for consideration of the electromagnetic interaction at nanoscale. At THz frequency, conductivity and skin depth of conventional copper metal decreases. Low con- ductivity of copper leads to degradation of radiation efficiency of copper antenna and small skin depth of copper leads to high propagation losses at THz frequencies. To overcome these difficulties in nanoscale antenna at THz band, materials other than conventional copper were explored by the microwave engineers. The outcome was the use of materials made of carbon atoms, such as, CNT and graphene that opens up the possibility to design nanostructure antennas at THz frequency. Although many THz antennas design using copper, graphene, and carbon nanotubes (CNTs) materials have been reported in the literature [11–20]. But on keen observation, it can be observed that the reason of using of such materials and the best material out of these, for THz antenna applications, is missing from antenna literature. Because this information is important from THz antenna designer’ s point of view, here, in this communication, we have made an effort to answer the query with technical justification. The phenomenon of surface plasmon polariton (SPP) is used in order give reasoning for the use of suitable materials for THz antenna applications. Performance of THz antennas is carried out by analyzing their surface conductivity and surface impedance. A specific length dipole was taken as the candidate antenna for the analysis. Simulation results show that the antenna made up of graphene has better performance in terms of radiation efficiency, direc- tivity, and compactness. For this reason, a thorough analysis has been done for the graphene plasmonic antenna. * Amalendu Patnaik apatnaik@ieee.org; apfecfec@iitr.ac.in 1 Department of Electronics and Communication Engineering, Indian Institute of Technology Roorkee, Roorkee 247 667, India Plasmonics (2018) 13:2353–2360 https://doi.org/10.1007/s11468-018-0761-z