The performance of a wearable antenna under bending conditions Designed on a Used Jeans for the ISM band

Haldia Institute of Technology Publishing Int.J.HIT.TRANSC:ECCN.Vol.12: Issue 1 A Available Online at www.hithaldia.in/locate/ECCN *Corresponding Address: [email protected] ORIGINAL CONTRIBUTION The performance of a wearable antenna under bending conditions Designed on a Used Jeans for the ISM band Subhrashil Nanda 1* , Tarit Sarkar 1* V.S.M. Manikpara, Jhargram, 721513, India Midnapore, 721102, India Email Id: [email protected] ABSTRACT In recent days, an increase in healthcare activities has prompted the importance of the Wearable Body Area Network (WBAN). In a WBAN, sensors and devices are integrated around the body to measure and track the blood pressure, temperature, oxygen level in b are collected and transmitted without hampering the comfort of the individual. A wearable antenna, which is placed either on the clothes or any other wearable material, is used to connect the WBAN with the for transferring data to the outer world. So far, many researchers have reported wearable antennas that are designed on lowloss engineered material. In our work, we have designed a wearable antenna on highly lossy, day-today used jeans. The jeans use dielectric probe kit using the Open tangent of jeans are tanδ=0.1152 and r GHz. The gain obtained is 1.8 dBi, and the radiation efficiency is 19%. The gain obtained is sufficient for indoor operation. The antenna is integrated on the human body; thus, the bending effect on the performance of the antenna is also s KEY WORDS: Wearable Antenna, Wearable Body Area Network (WBAN), ISM Band 1. INTRODUCTION The use of electronic gadgets in the healthcare sector is increasing day by day to measure track patients’ health conditions. The sensors and devices that are integrated around the body to measure and track parameters like blood pressure, temperature, oxygen level in blood, pulse rate, etc., form the WLAN. These data are transmitted to the outer world by establishing a connection between the LAN and WLAN wirelessly. It must be wireless, considering the mobile condition of the patient. Therefore, the wearable antenna integrated on the clothes or Haldia Institute of Technology Publishing International Journal of HIT Transaction on ECCN A (2025)Page 40-48 ISSN: 0973-6875 Available Online at www.hithaldia.in/locate/ECCN All Rights Reserved [email protected] DOI: 10.5281/zenodo.17499913 The performance of a wearable antenna under bending conditions Designed on a Used Jeans for the ISM band , Tarit Sarkar 2 and RajendraProsad Ghosh 3 V.S.M. Manikpara, Jhargram, 721513, India . 2 Vidyasagar University, Midnapore, 721102, India, 3 Vidyasagar University, In recent days, an increase in healthcare activities has prompted the importance of the Wearable Body Area Network (WBAN). In a WBAN, sensors and devices are integrated around the body to measure and track the blood pressure, temperature, oxygen level in b lood, pulse rate, etc. WBAN ensures that the data are collected and transmitted without hampering the comfort of the individual. A wearable antenna, which is placed either on the clothes or any other wearable material, is used to connect the WBAN with the for transferring data to the outer world. So far, many researchers have reported wearable antennas that are loss engineered material. In our work, we have designed a wearable antenna on highly day used jeans. The jeans use d here is collected from a local market. It is characterized in the dielectric probe kit using the Open -Ended Coaxial Probe technique. The dielectric and r =1.7976, respectively. The antenna is designed to GHz. The gain obtained is 1.8 dBi, and the radiation efficiency is 19%. The gain obtained is sufficient for indoor operation. The antenna is integrated on the human body; thus, the bending effect on the performance of the antenna is also s tudied. The antenna is optimized for optimal performance. Wearable Antenna, Wearable Body Area Network (WBAN), ISM Band The use of electronic gadgets in the healthcare sector is increasing day by day to measure and track patients’ health conditions. The sensors and devices that are integrated around the body to measure and track parameters like blood pressure, temperature, oxygen level in blood, pulse rate, etc., form the WLAN. These data are outer world by establishing a connection between the LAN and WLAN wirelessly. It must be wireless, considering the mobile condition of the patient. Therefore, the wearable antenna integrated on the clothes or any otherwearable things is suitable to establi the link [12]. The wearable antennas reported so far are designed on engineered low which also increases the cost [3 we have used highly lossy, day to design wearable antennas. Since wearable antennas are wearable garments without hampering the comfort of the individual, a planar structure configuration is suitable for the purpose. Specific absorption rate (SAR) plays an important role here. The back radiation of the International Journal of HIT Transaction on ECCN P a g e | 40 The performance of a wearable antenna under bending conditions Vidyasagar University, In recent days, an increase in healthcare activities has prompted the importance of the Wearable Body Area Network (WBAN). In a WBAN, sensors and devices are integrated around the body to measure and lood, pulse rate, etc. WBAN ensures that the data are collected and transmitted without hampering the comfort of the individual. A wearable antenna, which is placed either on the clothes or any other wearable material, is used to connect the WBAN with the LAN for transferring data to the outer world. So far, many researchers have reported wearable antennas that are loss engineered material. In our work, we have designed a wearable antenna on highly d here is collected from a local market. It is characterized in the constant and loss =1.7976, respectively. The antenna is designed to resonate at 2.45 GHz. The gain obtained is 1.8 dBi, and the radiation efficiency is 19%. The gain obtained is sufficient for indoor operation. The antenna is integrated on the human body; thus, the bending effect on the tudied. The antenna is optimized for optimal performance. Wearable Antenna, Wearable Body Area Network (WBAN), ISM Band any otherwearable things is suitable to establi sh 2]. The wearable antennas reported so far are designed on engineered low -loss fabric, which also increases the cost [3 -6]. In our work, we have used highly lossy, day -to-day used jeans Since wearable antennas are integrated with wearable garments without hampering the comfort of the individual, a planar structure configuration is suitable for the purpose. Specific absorption rate (SAR) plays an important role here. The back radiation of the Subhrashil Nanda et. al. / Int.J.HIT.TRANSC:ECCN. Vol12: Issue 1A(2025) ISSN: 0973-6875 DOI: 10.5281/zenodo.17499913 P a g e | 41 patch antenna is very poor because of the presence of the Ground plane, thereby reducing the SAR value [7-10]. Bin Hu et. al. have designed two dipole antennas on a low-loss felt fabric for wearable applications [3]. B. Mandalet. al. have reported a circular-shaped monopole printed antenna on low-loss cotton fabric [4]. A rectangular-shaped patch antenna designed on low-loss jeans substrate for the 2.45GHz ISM band is reported by Sweety Purohit and Falguni Raval [6]. A wearable antenna may deform and bend while being worn on the body. It affects the resonant frequency and antenna performance. Lingnan Song and YahyaRahmat-Samii have studied the bending effect on a patch antenna [11]. In another study by Ivo Locher et al., a purely textile wearable antenna was designed to resonate at 2.4GHz and studied the bending effect [12]. In our work, we have used day-to-day jeans as the substrate to design the wearable antenna. The jeans is collected from a local market and is characterized using Open Open-Ended Coaxial Probe (OECP) technique. The dielectric constant of the material is 1.7976, and the loss tangent is 0.1125. The thickness of the single-layer jeans is 0.425mm. The jeans fabric is highly lossy compared to an engineered wearable material [13]. The highly lossy material poses a challenge to designing antennas as it results in poor gain and efficiency. In our previous work, we have designed and reported a wearable antenna using a single layer of the same lossy jeans. The antenna has a gain of -9.26 dBi and a radiation efficiency of 1.83% at 2.4GHz [13]. The poor gain and radiation efficiency are due to the high loss of the material. In our present work, the antenna height is optimized to improve the gain and efficiency. The antenna is designed on five layers of jeans; thereby, the height of the substrate is increased to 2.125mm. A wearable antenna is integrated with cloth, which might bend and tends to take a curvature depending on the shape of the body parts, like biceps, thighs, belly, back, etc. The radius of curvature depends on the location of the body where the antenna is integrated. We have studied the bending effect on the resonant frequency, radiation efficiency, and radiation pattern. The performance is studied for different radii of curvature. It is found that the resonant frequency shift is negligible, but the 2.45 GHz ISM band remains unchanged. The gain remains greater than 1.5 dBi, and the radiation efficiency is greater than 19 % for all radii of curvature. The designed antenna may be used for health monitoring, tracking, and management systems, fitness trackers, for health care data transmission, and the Internet of Things, etc. The antenna has been designed, and the performances are studied in the Finite Element Method (FEM) based simulator CST Microwave Studio. 2. ANTENNA DESIGN AND RESULTS The geometry of the proposed antenna is shown in Fig. 1.The width of the patch (W), the effective dielectric constant (  ), and the length (L) are calculated using equations (1), (2), and (3)[14].  = 2    +1 2 (1) Where fr = Resonant frequency, C = Speed of light.   =  +1 2+  −1 21 +12ℎ    (2)  = 2    −2 △  (3) Where, ∆L is the increased length of the patch due to fringing effect, and it is calculated using equation (4) [14]. Subhrashil Nanda et. al. / Int.J.HIT.TRANSC:ECCN. Vol12: Issue 1A(2025) ISSN: 0973-6875 DOI: 10.5281/zenodo.17499913 P a g e | 42 The calculated length (L) and Width(W) of the patch are 44.22 mm and 51.73mm, respectively. Here inset feeding technique is used. The antenna is simulated using calculated dimensions on FEM based CST Microwave Studio [15] at different bending conditions. △ =0.412ℎ!  +0.3"# $ % +0.264' !  −0.258"# $ % +0.8' (4) 2.1 OPTIMIZED DIMENSIONS OF THE ANTENNA The optimized dimensions of the antenna under flat conditions are tabulated in Table 1. Table 1: Optimized dimensions of the antenna Variables Optimized values Dielectric constant (  r ) 1.7976 Loss tangent (tan δ) 0.1152 Substrate height (h) 2.125 mm Patch length (L) 42 mm Patch width (W) 67 mm Ground Length (LG) 120 mm Ground Width (WG) 120 mm Inset Depth (ID) 4.8 mm Inset Spacing (IS) 4.9 mm Feed Length (LF) 20 mm Feed Width (WF) 1.8 mm Subhrashil Nanda et. al. / Int.J.HIT.TRANSC:ECCN. Vol12: Issue 1A(2025) ISSN: 0973-6875 DOI: 10.5281/zenodo.17499913 P a g e | 43 Figure 1: Geometry of the antenna The geometry and dimensions of the antenna are shown in Fig. 1. The antenna is simulated under different bending conditions, but the dimensions are kept unchanged. The pictures of the antenna at different radii of curvature are shown in Fig. 2. Simulated S11 plots under different bending conditions are shown in Fig. 3.Simulated Gain vs frequency plots under different bending conditions are shown in Fig. 4. Simulated Radiation efficiency vs frequency plots under different bending conditions are shown in Fig. 5. Simulated Co and Cross-Pole Radiation patterns at 2.45GHz under different bending conditions are shown in Fig. 6. Simulated 3D Radiation patterns at 2.45 GHz under different Bending Conditions are shown in Fig. 7. Subhrashil Nanda ISSN: 0973-6875 DOI: 10.5281/zenodo.17499913 Figure 2: The pictures of the antenna at (A) Without Bending, (B) Bending with Radius of Curvature 300mm, (C) Bending with Radius of Curvature 600mm, (D) Bending with Radius of Curvature 900mm. . Figure 3: Simulated S Fig. 3. Simulated S Subhrashil Nanda et. al. / Int.J.HIT.TRANSC:ECCN. Vol 12 DOI: 10.5281/zenodo.17499913 Figure 2: The pictures of the antenna at (A) Without Bending, (B) Bending with Radius of Curvature 300mm, (C) Bending with Radius of Curvature 600mm, (D) Bending with Radius of Curvature 900mm. Figure 3: Simulated S 11 Plots under different bending conditions. Simulated S 11 Plots under different bending conditions. 12 : Issue 1A(2025) P a g e | 44 Figure 2: The pictures of the antenna at (A) Without Bending, (B) Bending with Radius of Curvature 300mm, (C) Bending with Radius of Curvature 600mm, (D) Bending with Radius of Curvature 900mm. Subhrashil Nanda ISSN: 0973-6875 DOI: 10.5281/zenodo.17499913 Figure 4: Simulated Gain vs Figure 5: Simulated Radiation Efficiency vs frequency plots under different bending conditions. Subhrashil Nanda et. al. / Int.J.HIT.TRANSC:ECCN. Vol 12 DOI: 10.5281/zenodo.17499913 Figure 4: Simulated Gain vs frequency plots under different bending conditions. Figure 5: Simulated Radiation Efficiency vs frequency plots under different bending conditions. 12 : Issue 1A(2025) P a g e | 45 frequency plots under different bending conditions. Figure 5: Simulated Radiation Efficiency vs frequency plots under different bending conditions. Subhrashil Nanda et. al. / Int.J.HIT.TRANSC:ECCN. Vol12: Issue 1A(2025) ISSN: 0973-6875 DOI: 10.5281/zenodo.17499913 P a g e | 46 Figure 6: Simulated Co-Pole and Cross-Pole radiation patterns for (A) Without Bending, (B) Bending with Radius of Curvature 300mm, (C) Bending with Radius of Curvature 600mm, (D) Bending with Radius of Curvature 900mm. Subhrashil Nanda et. al. / Int.J.HIT.TRANSC:ECCN. Vol12: Issue 1A(2025) ISSN: 0973-6875 DOI: 10.5281/zenodo.17499913 P a g e | 47 Figure 7: Simulated 3D Radiation patterns at 2.45 GHz for (A) Without Bending, (B) bending with a Radius of Curvature 300mm, (C) bending with a Radius of Curvature 600mm, (D) bending with a Radius of Curvature 900mm. 3. CONCLUSION In this research work, a wearable antenna is designed to resonate at the 2.45 GHz ISM band on highly lossy day-to-day used jeans, and the antenna dimensions are optimized for different bending situations to get optimum performance, keeping the resonant frequency unchanged. The antenna is designed on day-to-day jeans, which reduces the cost and technical complexity, and also, the antenna performance is good enough to use in WBAN for short-distance communication. Subhrashil Nanda et. al. / Int.J.HIT.TRANSC:ECCN. Vol12: Issue 1A(2025) ISSN: 0973-6875 DOI: 10.5281/zenodo.17499913 P a g e | 48 The antenna fabrication and experimental verification are in progress. The designed antenna may be used for health monitoring, tracking, and management systems, fitness trackers, various health care data transmission, Internet of Things, etc. References: [1]. Cavallari, R., Martelli, F., Rosini, R., Buratti, C., Verdone, R.: A Survey on Wireless Body Area Networks: Technologies and Design Challenges. IEEE communications surveys & tutorials, 16(3), 1635-1657 (2014). [2]. Arefin, M. T., Ali, M. H., Haque, A. F.: Wireless Body Area Network: An Overview and Various Applications. Journal of Computer and Communications, 5(07), 53 (2017). [3]. Hu, B., Gao, G. P., He, L. L., Cong, X. D., Zhao, J. N.: Bending and On-Arm Effects on a Wearable Antenna for 2.45 GHz Body Area Network. IEEE Antennas and Wireless Propagation Letters (15), 378-381 (2015). [4]. Mandal, B., Mukherjee, B., Chatterjee, A., Parui, S. K.: Design of Printed Body wearable Textile Antenna for Broadband Application. In: 2013 IEEE Applied Electromagnetics Conference (AEMC), pp. 1-2. IEEE (2013, December). [5]. Ashyap, A. Y., Abidin, Z. Z., Dahlan, S. H., Majid, H. A., Shah, S. M., Kamarudin, M. R., Alomainy, A.: Compact and Low-Profile Textile EBG-Based Antenna for Wearable Medical Applications. IEEE Antennas and Wireless Propagation Letters (16), 2550-2553 (2017). [6]. Purohit, S., Raval, F.: Wearable -Textile Patch Antenna using Jeans as Substrate at 2.45 GHz. International Journal of Engineering Research & Technology (IJERT)3(5), (2014). [7]. Anbalagan, A., Sundarsingh, E. F., Ramalingam, V. S., Samdaria, A., Gurion, D. B., Balamurugan, K.: Realization and Analysis of a Novel Low-Profile Embroidered Textile Antenna for Real-time Pulse Monitoring. IETE Journal of Research 68(6), 4142-4149 (2022). [8]. Werfelli, H., Tayari, K., Chaoui, M., Lahiani, M., Ghariani, H.: Design of Rectangular Microstrip Patch Antenna. In: 2016 2nd International Conference on Advanced Technologies for Signal and Image Processing (ATSIP), pp. 798-803. IEEE (2016, March). [9]. Kai-Fong, L.: Microstrip patch antennas—basic properties and some recent advances. Journal of Atmospheric and Terrestrial Physics 51(9-10), 811-818 (1989). [10]. Memon, A. W., de Paula, I. L., Malengier, B., Vasile, S., Van Torre, P., Van Langenhove, L.: Breathable Textile Rectangular Ring Microstrip Patch Antenna at 2.45 GHz for Wearable Applications. Sensors, 21(5), 1635 (2021). [11]. Song, L., Rahmat-Samii, Y.: A Systematic Investigation of Rectangular Patch Antenna Bending Effects for Wearable Applications. IEEE Transactions on Antennas and Propagation 66(5), 2219-2228 (2018). [12]. Locher, I., Klemm, M., Kirstein, T., Troster, G.: Design and Characterization of Purely Textile Patch Antennas. IEEE Transactions on Advanced Packaging 29(4), 777-788 (2006). [13]. Nanda, S., Ghosh, R.P.: Wearable Antennas on Day-to-Day Used Jeans Pant for Body Area Network Application, In: 7th Regional Science and Technology Congress 2024-2025: Region4, pp.105 (2025). [14]. Balanis, C. A.: Antenna theory: analysis and design. 3rd ed. John Wiley & Sons (2016). [15]. CST Corporation. (2022). CST Microwave Studio. [Online]. Available: http://www.cst.com.