FLEXIBLE, COMPACT AND HIGHLY EFFICIENT GRAPHENE-BASED ULTRA-WIDEBAND ANTENNA FOR WEARABLE APPLICATIONS

Abstract

This article presents the designs and analyses of a co-planar ultra-wideband monopole antenna using graphene as a conductive patch. A graphene-based film (GBF) is used as the radiating conductive layer of the antenna, and a Polydimethylsiloxane (PDMS) is used as a substrate. Since both layers are flexible, they are very suitable for use in wearable technologies. In this study, two basic antenna structures are studied. The design-1 antenna covers 3-11 GHz bandwidth. The simulated antenna efficiency is obtained as 72% at 10 GHz. The antenna size is 30 mm×23.2 mm. The second designed antenna (design-2), stands out with its optimizations, is designed in a smaller size, high gain and wide band features. The size of the second antenna has been reduced to 28 mm×21 mm. Although the conductive graphene layer of the antenna was replaced with a higher conductivity, the substrate material remained the same. In the second antenna design, 3.3-30 GHz ultra-bandwidth and 83% efficiency at 25 GHz have been achieved. In addition, new antenna designs with different conductor and substrate properties on the second antenna design are proposed in this study. The effect of antenna bending was also examined and comparative analyses of the obtained results were made in terms of properties such as efficiency, gain, and radiation pattern. In addition to the use of flexible materials in both the substrate and the conductive layer of the designed antennas, their smaller dimensions, broadband structures and high efficiencies allow these antennas to be used as good candidates in wearable technologies.