Discipline: Technology and Engineering
Subcategory: Electrical Engineering
Room: Exhibit Hall A
Adrian Astros - Florida International University
Co-Author(s): Gianfranco Perez, Edwin Najera, Akash Biswas, Abdul-Sattar Kaddour, and Stavros V. Georgakopoulos, Florida International University, FL
Wireless communication systems for several emerging applications, such as wearable and foldable systems, require flexible and reliable conductive materials to build their antennas. In the literature, various conductive materials and methods for constructing non-textile and fully textile antennas have been discussed . However, no comparison of these materials and methods has been performed in a consistent paradigm. In addition, such a comparison is important as it can provide researchers the needed data for selecting the proper materials and methods for different applications. The aim of this research work is to characterize the losses of various conductive materials for radio frequency (RF) applications. The materials tested include copper clad, copper tape, silver fabric, 60% water 40% silver ink compound, silver-copper compound spray, and conductive thread. To provide a comparison on a consistent paradigm, a copper-clad Microstrip Transmission Line (MTL) is designed to operate at 1 GHz . To provide a fair comparison, all selected materials are placed on FR-4 substrates except the conductive fabric substrate. The percentage of power loss is measured using a vector network analyzer. Our measurements show that the power loss at 1GHz is: 14% for copper clad, 14% for copper tape, 14% for conductive thread, 18% for silver ink compound, 23% for silver fabric, and 26% for silver-copper compound spray. Also, the different materials are compared in terms of their conductivity, flexibility and ease of processing. Specifically, manual processing of liquids is cumbersome and dimensional tolerances are difficult to control. Copper tape, silver ink, and silver-copper compound spray suffer from poor malleability and tend to crack under folding, while conductive e-threads exhibit low power losses and better performance under folding. In conclusion, this research provides important data for conductive materials suitable for foldable and bendable antennas.
References:  L. Corchia, G. Monti and L. Tarricone, ‘Wearable Antennas: Nontextile Versus Fully Textile Solutions,’ IEEE Antennas and Propagation Magazine, vol. 61, no. 2, pp. 71-83, April 2019.
 D. Vital, J. Zhong, S. Bhardwaj and J. L. Volakis, ‘Loss-Characterization and Guidelines for Embroidery of Conductive Textiles,’ 2018 IEEE International Symposium on Antennas and Propagation & USNC/URSI National Radio Science Meeting, Boston, MA, 2018, pp. 1301-1302.  D. Vital, J. Zhong, S. Bhardwaj and J. L. Volakis, ‘Loss-Characterization and Guidelines for Embroidery of Conductive Textiles,’ 2018 IEEE International Symposium on Antennas and Propagation & USNC/URSI National Radio Science Meeting, Boston, MA, 2018, pp. 1301-1302.
Funder Acknowledgement(s): This work was supported by -National Science Foundation under grant EFRI 1332348 (which includes a REM grant) -Air Force Office of Scientific Research under grant FA9550-18-1-0191.
Faculty Advisor: Stavros V. Georgakopoulos, firstname.lastname@example.org
Role: I designed, fabricated and measured microstrip lines using different conductive materials.