This paper presents a compact CPW fed circularly polarized AMC integrated monopole antenna with low SAR and high gain for 2.4 GHz WBAN applications. The proposed design is achieved through a four-stage progression. Stage-1 consists of a straight monopole with an extended vertical stub at one of the ground planes to generate circular polarization. In stage-2, a novel ring-type isotropic AMC is implemented beneath the monopole antenna to mitigate the antenna's back radiations towards the human body. On the body at `0' mm distance, it reduces the SAR by 99.47% and increases the impedance bandwidth, radiation efficiency, and gain to 480 MHz, 77% and 7.1 dBi, respectively. However, there is a decrease in AR bandwidth that indicates AR > 3-dB, which is compensated in stage-3 by optimizing the monopole. The optimization results an AR BW of 190 MHz and a size reduction of monopole antenna by 30.862%. Due to the size reduction of monopole with same AMC, the SAR reduction and peak gain are improved to 99.63% and 7.4 dBi, respectively. In Stage-4, the 3×3AMC is replaced by 2×2 AMC, results in total size and SAR reduction of 55.56% and 97.72% respectively. Stage-4 provides a simulated impedance bandwidth of 350 MHz, peak gain of 6.4 dBi and AR bandwidth of 170MHz, whereas the fabricated structure on felt substrate provides 650 MHz, 6.5 dBi and 150 MHz respectively.
2. Gareth, A. C. and G. S. William, "Antennas for over body surface communication at 2.45 GHz," IEEE Trans. Antennas Propag., Vol. 57, No. 4, 844-855, 2009.
doi:10.1109/TAP.2009.2014525
3. Linda, A. Y. P., J. S. Ping, and Y. Sen, "A high fidelity all textile UWB antenna with low back radiation for off-body WBAN applications," IEEE Trans. Antennas Propag., Vol. 64, No. 2, 757-760, 2016.
doi:10.1109/TAP.2015.2510035
4. Adel, Y. I. A., Z. A. Zuhairiah, and H. D. Samsul, "Compact and low profile textile EBG-based antenna for medical wearable applications," IEEE Antennas Wireless Propag. Lett., Vol. 14, 2550-2553, 2017.
5. Sen, Y., J. S. Ping, and A. E. V. Guy, "Low-profile dual-band textile antenna with artificial magnetic conductor plane," IEEE Trans. Antennas Propag., Vol. 62, No. 12, 6487-6490, 2014.
doi:10.1109/TAP.2014.2359194
6. Sangeetha, V. and F. S. Malathi, "Dual-band EBG integrated monopole antenna deploying fractal geometry for wearable applications," IEEE Antennas Wireless Propag. Lett., Vol. 14, 249-252, 2015.
7. Alemaryeen, A. and S. Noghanian, "Crumpling effects and specific absorptions rate of flexible AMC integrated antennas," IET Microw. Antennas Propag., Vol. 12, No. 4, 627-635, 2018.
doi:10.1049/iet-map.2017.0652
8. Natale, A. D. and E. D. Giampaolo, "A reconfigurable all-textile wearable UWB antenna," Progress In Electromagnetic Research C, Vol. 106, 31-43, 2020.
doi:10.2528/PIERC20031202
9. Osman, M. A. R., M. K. A. Rahim, N. A. Samsuri, H. A. M. Salim, and M. F. Ali, "Embroidered full textile wearable antenna for medical monitoring applications," Progress In Electromagnetics Research, Vol. 117, 321-337, 2011.
doi:10.2528/PIER11041208
10. Balarami Reddy, B. N., P. Sandeep Kumar, T. Rama Rao, N. Tiwari, and M. Balachary, "Design and analysis of wideband monopole antennas for flexible/wearable wireless device applications," Progress In Electromagnetics Research M, Vol. 62, 167-174, 2017.
doi:10.2528/PIERM17092107
11. Sherif, R. Z., A. A. Mahmoud, and G. Abdelhamid, "New thin wide-band bracelet-like antenna with low SAR for on-arm WBAN applications," IET Microw. Antennas Propag., Vol. 13, No. 8, 1219-1225, 2019.
doi:10.1049/iet-map.2018.5801
12. Jiang, Z. H., C. Zheng, and T. Yue, "Compact, highly efficient, and fully flexible circularly polarized antenna enabled by silver nanowires for wireless body-area networks," IEEE Trans. Biomed. Curcuits Syst., Vol. 11, No. 4, 920-932, 2017.
doi:10.1109/TBCAS.2017.2671841
13. Muhammad, A. B. A., S. N. Symeon, and A. A. Macro, "Compact EBG-backed planar monopole for BAN wearable applications," IEEE Trans. Antennas Propag., Vol. 65, No. 2, 453-463, 2017.
doi:10.1109/TAP.2016.2635588
14. Zhi, H. J., E. B. Donovan, and E. S. Peter, "A Compact low-profile meta-surface enabled antenna for wearable medical body-area network devices," IEEE Trans. Antennas Propag., Vol. 62, No. 8, 4021-4030, 2014.
doi:10.1109/TAP.2014.2327650
15. Haider, R. K., I. A. Ayman, and M. A. Hussain, "Analysis of radiation characteristics of conformal arrays using adaptive integral method," IEEE Trans. Antennas Propag., Vol. 61, No. 2, 524-531, 2013.
doi:10.1109/TAP.2012.2223449
16. Simone, G., C. Filippo, and F. Filippo, "Wearable inject-printed wideband antenna by using miniaturized AMC for sub-GHz applications," IEEE Antennas Wireless Propag. Lett., Vol. 15, 1927-1930, 2016.
17. Mohamed, E., A. A. Mohmoud, and M. E. Hadia, "Gain enhancement of a compact thin flexible reflector-based asymmetric meander line antenna with low SAR," IET Microw. Antennas Propag., Vol. 12, No. 4, 627-635, 2018.
doi:10.1049/iet-map.2017.0652
18. Mohamed, E., A. A. Mahmoud, and M. E. Hadia, "A wearable dual-band low profile high gain low SAR antenna AMC backed for WBAN application," IEEE Trans. Antennas Propag., Vol. 67, No. 10, 6378-6388, 2019.
doi:10.1109/TAP.2019.2923058
19. Wang, M., Z. Yang, and J. Wu, "Investigation of SAR reduction using flexible antenna with meta material structurein wireless body area network," IEEE Trans. Antennas Propag., Vol. 66, No. 6, 3076-3086, 2018.
doi:10.1109/TAP.2018.2820733
20. Abirami, B. S. and F. S. Esther, "EBG-backed flexible printed Yagi-Uda antenna for on-body communication," IEEE Trans. Antennas Propag., Vol. 65, No. 7, 3762-3765, 2017.
doi:10.1109/TAP.2017.2705224
21. Sangkil, K., J. R. Yu, and L. Hoseon, "Monopole antenna with inject-printed EBG array on paper substrate for wearable applications," IEEE Antennas Wireless Propag. Lett., Vol. 11, 663-666, 2012.
22. Benjamin, S. C. and S. Atif, "Utilizing wide band AMC structures for high-gain inject printed antennas on lossy paper substrate," IEEE Antennas Wireless Propag. Lett., Vol. 12, 76-79, 2013.
23. Benjamin, S. C. and S. Atif, "Wearable AMC backed near-endfire antenna for on-body communications on latex substrate," IEEE Trans. Compon. Packag. Manuf. Technol., Vol. 6, No. 3, 346-358, 2016.
doi:10.1109/TCPMT.2016.2521487
24. Means, D. L. and K. W. Chan, "Evaluating compliance with FCC guidelines for human exposure to radiofrequency electromagnetic fields,", Office of Engineering and Technology Federal Communication Commission FCC, Washington D.C., 2001.
25., "Commision implementing decision (EU) 2016/537," Official Journal of the European Union, 2016.
26. Faruqqque, M. R. I., M. I. Hossain, and M. T. Islam, "Low specific absorption rate microstrip patch antenna for cellular phone applications," IET Microw. Antennas Propag., Vol. 9, No. 14, 1540-1546, 2015.
doi:10.1049/iet-map.2014.0861
27. Roy, B. V. B. S., K. Asimina, and P. E. Karu, "UWB wearable antenna with full ground plane based on PDMS-embedded conductive fabric," IEEE Antennas Wireless Propag. Lett., Vol. 17, No. 3, 493-496, 2018.
doi:10.1109/LAWP.2018.2797251
28. Hertleer, C., H. Rogier, L. Vallozzi, and L. van Langenhove, "A textile antenna for off-body communication integrated into protective clothing for firefighters," IEEE Trans. Antennas Propag., Vol. 57, No. 4, 919-925, 2009.
doi:10.1109/TAP.2009.2014574
29. Locher, I., M. Klemm, T. Kirstein, and G. Troster, "Design and characterization of purely textile patch antennas," IEEE Trans. Adv. Packag., Vol. 29, No. 4, 777-788, 2006.
doi:10.1109/TADVP.2006.884780
30. Ullah, U., I. B. Mabrouk, and S. Koziel, "A compact circularly polarized antenna with directional pattern for wearable off-body communications," IEEE Antennas Wireless Propag. Lett., Vol. 18, 2523-2527, 2019.
doi:10.1109/LAWP.2019.2942147
31. Atrash, M. E., O. F. Abdalgalil, I. S. Mamoud, M. A. Abdalla, and S. R. Zahran, "Wearable high gain low SAR antenna loaded with backed all-textile EBG for WBAN applications," IET Microw. Antennas Propag., Vol. 14, No. 8, 791-799, 2020.
doi:10.1049/iet-map.2019.1089
32. Zhang, K. and G. A. E. Vandenbosch, "A novel design approach for compact wearable antennas based on metasurfaces," IEEE Trans. Antennas Propag., Vol. 14, No. 4, 918-927, 2020.
33. Joshi, R., E. F. N. M. Hussin, P. J. Soh, M. F. Jamlos, H. Lago, A. A. A. Hadi, and S. K. Podilchak, "Dual-band, dual-sense textile antenna with AMC backing for localization using GPS and WBAN/WLAN," IEEE Access, Vol. 8, 89468-89478, 2020.
doi:10.1109/ACCESS.2020.2993371
34. Gao, G., R. Zhang, C. Yang, H. Meng, W. Geng, and B. Hu, "Microstrip monopole antenna with a novel UC-EBG for 2.4 GHz WBAN applications," IET Microw. Antennas Propag., Vol. 13, No. 13, 2319-2323, 2019.
doi:10.1049/iet-map.2019.0271
35. Balakrishnan, S. A. and E. F. Sudarsingh, "Conformal self-balanced EBG integrated printed folded dipole antenna for wireless body area networks," IET Microw. Antennas Propag., Vol. 13, No. 14, 2480-2485, 2019.
doi:10.1049/iet-map.2019.0029
36. Saeed, S. M., C. A. Balanis, C. R. Birtcher, A. C. Durgun, and H. N. Shaman, "Wearable flexible reconfigurable antenna integrated with artificial magnetic conductor," IEEE Antennas Wireless Propag. Lett., Vol. 16, 2396-2399, 2017.
doi:10.1109/LAWP.2017.2720558
37. Yun, S., D. Y. Kim, and S. Nam, "Folded cavity-backed crossed-slot antenna," IEEE Antennas Wireless Propag. Lett., Vol. 14, 36-39, 2015.
doi:10.1109/LAWP.2014.2354517
38. Lui, K. W., O. H. Murphy, and C. Toumazou, "A wearable wideband circularly polarized textile antenna for effective power transmission on a wireless-powered sensor platform," IEEE Trans. Antennas Propag., Vol. 61, No. 7, 3873-3876, 2013.
doi:10.1109/TAP.2013.2255094
39. Kaivanto, E. K., M. Berg, E. Salonen, and P. de Maagt, "Wearable circularly polarized antenna for personal satellite communication and navigation," IEEE Trans. Antennas Propag., Vol. 59, No. 12, 4490-4496, 2011.
doi:10.1109/TAP.2011.2165513
40. Ismail, M. F., M. K. A. Rahim, E. I. S. Saadon, and M. S. Mohd, "Compact circularly polarized textile antenna," Proc. 2014 IEEE Symp. Wireless Tech. Appl., 134-136, Oct. 2014.
41., Specification Sheet-Felt Sheet RS Component Inc., 2013.