International Journal of Innovative Technology and Exploring Engineering (IJITEE) ISSN: 2278-3075, Volume-9 Issue-1, November 2019 1515 Published By: Blue Eyes Intelligence Engineering & Sciences Publication Retrieval Number: A4344119119/2019©BEIESP DOI: 10.35940/ijitee.A4344.119119 Dual Band Wearable Antenna for IOT Applications Devendra Kumar, Dhirendra Mathur Abstract: A dual band wearable antenna operating on 2.6 GHz (2570-2620 MHz FDD/TDD) and 5.2 GHz (802.11a) bands for Body Area Network (BAN) application is presented. The stack substrates of Felt and ethylene-vinyl acetate (EVA) foam are used to make the structure flexible. Maximum gain of 2.75 and front to back ratio of 8.35 is achieved on industrial scientific and medical (ISM) band. Additional bandwidth enhancement has been achieved by creating slots on partial ground plane. The calculated specific absorption rate (SAR) value is 1.33 W/kg for 1 g of body tissue. Simulated and measured results are presented for the proposed structure. Keywords: BAN, EVA, Gain, ISM, Multiband, SAR, Wearable I. INTRODUCTION Wireless body centric communication provides various applications in the areas such as patient’s health monitoring, defense security and public entertainment. The antennas integrated with wearing cloths and being in close proximity to the body are more suitable for personal wireless devices required for maintaining quality of service regardless of body movements. Because of the available large space on body, the wearable electronic devices do not have any limitation of size and shape [1,2]. In comparison to traditional antennas, body-worn antennas are to be flexible and better suited for integration with wireless communication devices. These applications motivate the design of antennas using materials with flexibility [3]. In the past, various textiles materials have been used to design various wearable devices [4-6]. Small printed antennas are widely reported in literature during last decade as referred in [7-9]. Small size printed antennas have low efficiency. Various configurations have been studied over the past years. The structures designed with Meta-material and fractal techniques help in reducing the size of microstrip antennas that show better efficiency [10]. A coplanar waveguide fed ring strip with stubs are proposed for UWB operation [11]. Biomedical implantable antenna for stimulation and neural signal recording devices is presented in [12] for providing power supply by inductive coupling. A printed circuit board based metal frame antenna [13] is proposed for health monitoring with wrist band wearable devices. An implantable loop antenna with circular polarization is proposed for ISM band operation in [14]. Implantable on chip antenna using CMOS technology is proposed in [15]. Biomedical printed MIMO antenna is designed for telemetry applications in [16]. In this work we have proposed a dual band wearable antenna with flexible substrate for the application of short range wireless communication in body area networks. Revised Manuscript Received on November 05, 2019. Devendra Kumar, Assistant Professor in department of Electronics & Communication Engineering in Rustamji Institute of Technology, Gwalior (India) since 16 Aug 2010. Dr Dhirendra Mathur, Head, Center of Nanotechnology and Dean Research, RTU Kota. II. ANTENNA DESIGN The simulated structure is displayed in fig.1. The ground plane of antenna is made up of copper tape of thickness 0.05 mm. The partial ground plane of rectangular shape (W9 x L9= 44x12 mm²) with symmetrical slots at left and right sides of ground plane is realized at one end of substrate. The two slots (W4 x L8= 7 mm x 8 mm) and (W5 x L8= 6 mm x 8 mm) are at left side and similar slots are at right side of the partial ground plane. A hexagonal shape parasitic element is connected with very thin strip (W10 x L7=01 x 12 mm) to rectangular ground plane. Each side (L6) of the hexagonal is of 15 mm. First substrate of felt material with relative permittivity (Ԑr) of 1.38, loss tangent (δ) of 0.044, W3=54 mm, L5=66 mm and thickness of 01 mm is placed above partial ground plane. Second substrate of EVA foam with relative permittivity (Ԑr) of 1.20, loss tangent (δ) of 0.02, W3=54 mm, L5=66 mm and height of 1.65 mm is stacked on first substrate with acrylic glue. The coplanar ground planes, feed and radiating patch consist of copper tape placed on second substrate. The size of each coplanar ground (W2 x L3) is 23 x 33.5 mm². The radiating patch is elliptical in shape with six segments. The lengths of major axis and minor axis of patch are 48 mm and 20 mm respectively. The lengths of sides are L1=24 mm and L2=14.14 mm. The length of microstrip feed (L4) is 35 mm and width (W1) is 2.5 mm. The gap between feed and coplanar ground is of 2.75 mm. The gap between coplanar ground and patch is of 1.5 mm. The partial ground plane and coplanar ground planes are connected with two shorting strips on either sides of feed to keep them on same potential. The different dimensions of antenna are shown in fig.1and table-I. (a) (b) Fig.1 Structure of Antenna: (a) Top view (b) Bottom View