Single-wall carbon nanotubes-based flexible monopole antenna with high radiation efficiency

Abstract This study examines the characteristics of single-wall carbon nanotube (SWCNT) antennas in both flat and bent configurations to comprehensively assess their properties as practical flexible antennas. Monopole antennas solely composed of SWCNT were fabricated, characterized by their high flexibility, light weight, and mechanical robustness. These antennas were tested under conditions representative of the operational environment of flexible antennas, and their reflection and radiation characteristics were analyzed. The gains of the SWCNT antennas, whether flat or bent, were nearly identical, and their radiation patterns were similar to those of traditional metal antennas. Using the Wheeler cap method, the radiation efficiencies for the flat and bent SWCNT antennas were measured at 80.0% and 83.7%, respectively, exceeding the 80% threshold considered practical for such applications. The high flexibility and efficiency of the antennas render them suitable for integration into wearable devices and other applications demanding non-standard shapes and surfaces.