This paper aimed to take closer steps towards real wearability by investigating the possibilities of designing and fabricating highly efficient and fully flexible wearable microstrip patch antenna for operating frequency of 5.8 GHz as a center frequency. Two types of conducting materials have been used for conducting parts: conventional metal plane and woven electro-textile material, while a non-conducting jeans fabric has been used as antenna substrate material. The dielectric constant εr = 1.78, and loss tangent tanδ = 0.085 of the jeans substrate measured by using two different methods. Also, the electromagnetic properties of the electro-textile are studied in details. The conductivity of e-textile cell is equal to 2.5×106 S/m and the surface impedance of e-textile cell equal to 0.0395+J18.4 Ω. Furthermore, the proposed wearable antenna may be attached to human body, so the specific absorption ratio (SAR) must be calculated. Finally, the proposed design is simulated by CST simulator version 2016, fabricated using folded copper and measured by Agilent8719ES VNA.
2. Langenhove, L. V., Smart Textiles for Medicine and Healthcare, CRC Press, Cambridge, England, 2007.
3. Park, S. and S. Jayaraman, "Wearable biomedical systems: Research to reality," IEEE International Conference on Portable Information Devices, May 2007.
4. Sankaralingam, S. and B. Gupta, "Development of textile antennas for body wearable applications and investigations on their performance under bent conditions," Progress In Electromagnetics Research B, Vol. 22, 53-71, 2010.
5. Kennedy, T. F., P. W. Fink, A. W. Chu, N. J. Champagne, G. Y. Lin, and M. A. Khayat, "Body-worn e-textile antennas: The good, the low mass, and the conformal," IEEE Transactions on Antennas and Propagation, Vol. 57, 910-918, 2009.
6. Ouyang, Y., E. Karayianni, and W. J. Chappell, "Effect of fabric patterns on electro-textile patch antennas," IEEE Antennas and Propagation Society International Symposium, Vol. 2B, 246-249, 2005.
7. Abbasi, M. A. B., S. S. Nikolaou, M. A. Antoniades, M. N. Stevanovic, and P. Vryonides, "Compact EBG-backed planar monopole for BAN wearable applications," IEEE Transactions on Antennas and Propagation, Vol. 65, No. 2, 453-463, Feb. 2017.
8. Lotfi, P., S. Soltani, and R. D. Murch, "Printed endfire beam-steerable pixel antenna," IEEE Transactions on Antennas and Propagation, Vol. 65, No. 8, 3913-3923, Aug. 2017.
9. Zhong, J., A. Kiourti, T. Sebastian, Y. Bayram, and J. L. Volakis, "Conformal load-bearing spiral antenna on conductive textile threads," IEEE Antennas and Wireless Propagation Letters, Vol. 16, 230-233, 2017.
10. Kiourti, A., C. Lee, and J. L. Volakis, "Fabrication of textile antennas and circuits with 0.1 mm precision ," IEEE Antennas and Wireless Propagation Letters, Vol. 15, 151-153, 2015.
11. Ouyang, Y. and W. J. Chappell, "High frequency properties of electro-textiles for wearable antenna applications," IEEE Transactions on Antennas and Propagation, Vol. 56, No. 2, Feb. 2008.
12. Hopkins, R. and C. Free, "Equivalent circuit for the microstrip ring resonator suitable for broadband materials characterization," IET Microwaves, Antennas & Propagation, Vol. 2, No. 1, 66-73, Feb. 2008.
13. Pozar, D. M., "Electromagnetic theory," Microwave Engineering, 3rd Edition, John Wiley and Sons, Inc., Hoboken, NJ, 2005.
14. Ahmed, M. I., M. F. Ahmed, and A. A. Shaalan, "Investigation and comparison of 2.4 GHz wearable antennas on three textile substrates and its performance characteristics," Open Journal of Antennas and Propagation, Vol. 5, 110-120, 2017.
15., , https://www.speag.com/products/dak/dielectric-measurements/.
16. Quirk, M. M., T. L. Martin, and M. T. Jones, "Inclusion of fabric properties in the e-textile design process," Proceedings of International Symposium on Wearable Computers, 37-40, 2009.
17. Locher, I., M. Klemm, T. Kirstein, and G. Troster, "Design and characterization of purely textile patch antennas," IEEE Trans. Adv. Pack., Vol. 29, 777-788, 2006.
18. Ouyang, Y. and W. J. Chappell, "High frequency properties of electrotextiles for wearable antenna applications," IEEE Transactions on Antennas and Propagation, Vol. 56, No. 2, 381-389, 2008.
19. Paul, C. R., Introduction to Electromagnetic Compatibility, 2nd Ed., Wiley, New York, 2006.
20. Quirk, M. M., T. L. Martin, and M. T. Jones, "Inclusion of fabric properties in the e-textile design process," Proceedings of International Symposium on Wearable Computers, 37-40, 2009.
21. Balanis, C. A., Antenna Theory: Analysis and Design, 2nd Ed., Wiley, New York, 1996.
22. IEEE C95.1-2005, "IEEE standards for safety levels with respect to human exposure to radio frequency electromagnetic fields, 3 kHz to 300 kHz,", Institute of Electrical and Electronics Engineers, New York, NY, 2005.
23. CST MICROWAVE STUDIO®, , help, http://www.cst.com.