Bengio, E. AmramSenic, DamirTaylor, Lauren W.Tsentalovich, Dmitri E.Chen, PeiyuHolloway, Christopher L.Babakhani, AydinLong, Christian J.Novotny, David R.Booth, James C.Orloff, Nathan D.Pasquali, Matteo2018-06-292018-06-292017Bengio, E. Amram, Senic, Damir, Taylor, Lauren W., et al.. "High efficiency carbon nanotube thread antennas." <i>Applied Physics Letters,</i> 111, (2017) AIP Publishing: https://doi.org/10.1063/1.4991822.https://hdl.handle.net/1911/102321Although previous research has explored the underlying theory of high-frequency behavior of carbon nanotubes (CNTs) and CNT bundles for antennas, there is a gap in the literature for direct experimental measurements of radiation efficiency. These measurements are crucial for any practical application of CNT materials in wireless communication. In this letter, we report a measurement technique to accurately characterize the radiation efficiency of λ/4 monopole antennas made from the CNT thread. We measure the highest absolute values of radiation efficiency for CNT antennas of any type, matching that of copper wire. To capture the weight savings, we propose a specific radiation efficiency metric and show that these CNT antennas exceed copper's performance by over an order of magnitude at 1 GHz and 2.4 GHz. We also report direct experimental observation that, contrary to metals, the radiation efficiency of the CNT thread improves significantly at higher frequencies. These results pave the way for practical applications of CNT thread antennas, particularly in the aerospace and wearable electronics industries where weight saving is a priority.engArticle is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.Journal articlehttps://doi.org/10.1063/1.4991822