International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395-0056
Volume: 10 Issue: 07 | July 2023
p-ISSN: 2395-0072
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A Wideband Wearable Antenna for ISM and WLAN Applications Kavisha Singh1, Dr. Nand Kishore2 1M. Tech Scholar, Dept. of Electronics Engineering, Harcourt Butler Technical University, Uttar Pradesh, India
2Assistant Professor, Dept. of Electronics Engineering, Harcourt Butler Technical University, Uttar Pradesh, India
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Abstract - A wideband slotted patch antenna with a partial
a triband electronic bandgap array antenna operating in WLAN and WiMAX bands. In [6] three forms of dual band (2.45 GHz and 5.2 GHz) antennas with electronic bandgap structure have been discussed. Though the use of EBG structure beneath the antenna makes them bulky. The authors of [7] have presented a semi flexible hybrid Moore fractal antenna operating in 1.38-1.8 GHz and 2.45-4.88 GHz bands. The proposed antenna has a compact geometry and lower values of SAR. A meander line patch antenna spanning frequencies between 2.36-2.46 GHz is discussed in [8]. In [9] the authors have proposed an antenna incorporating a foam spacer operating at 2.45 GHz. A wideband minkowski fractal geometry-based antenna is presented in [10] with operation in frequency range of 700 MHz to 4.71 GHz. The authors of [11] have presented an IDE bandgap unit cell-based antenna for use in MBAN applications. In [12] a 2.45 GHz ISM band antenna with double flexible substrates is discussed. In [13] an ISM band antenna with denim as a substate is presented. However, textile antennas are susceptible to water and moisture content.
ground for wearable applications is presented in this article. The dimensions have been optimized to obtain a compact structure of 30x20x0.8 on FR4 epoxy substrate. A triple band operation with resonant frequencies at 2.4 GHz, 3.8 GHz and 5.8 GHz is observed. A peak gain of 3.7 dB is found for the center frequency of 5.8 GHz with 97% efficiency. The average value of SAR simulated on a three-layer human body phantom for an input power of 1 mW is 0.0175 W/kg. The antenna is appropriate for implementation in Wireless Body Area Networks. Key Words: Wearable, Complementary split ring resonator, Return loss, SAR
1.INTRODUCTION The world of wearables has gained a tremendous increase in the last decade owing to their relevance in the areas of health monitoring, diagnosis, tracking and location sensing [1]. Wearable antennas are most commonly developed for operation at specific frequencies keeping in view the area of application. These antennas are most widely used in Wireless Body Area Networks (WBAN) due to their promise in various healthcare applications. A set of frequency bands are designated to commercial WBAN systems including frequencies in the range of 402 MHz to 10.6 GHz [2]. The realization of wearable antennas has strong dependence on the lossy nature of body tissues. The close proximity of human body, structural deformation, robustness and wearer’s comfort are the crucial aspects in wearable antenna configuration. These antennas also tend to suffer from frequency detuning [1]. As these antennas form a part of on body communication system, they need to be light weight, compact and water resistant.
This work presents a triple band compact wearable antenna with an acceptable value of SAR. The antenna shows a wideband operation and is suitable for WBAN applications. The comparatively simple design and smaller size as compared to previous works makes it a good alternative for wearable applications. Free space and on body analysis have been performed for the proposed antenna. The reflection coefficient, acceptable gain and on body SAR simulations also show the feasibility of the proposed work.
2. GEOMETRY The antenna is structured on a FR-4 epoxy substrate with a relative permittivity of 4.4 and a dissipation factor of 0.02. A high dielectric constant substrate was utilized to bring down the measurements of the proposed antenna [14]. The resulting geometry has compact dimensions of 30mm x 20mm x 0.8mm. The design process started with the modelling of a square shaped patch and a partial ground. The limited size of ground plane helps in broadening the bandwidth of antenna [15]. Four square shaped slots at the corners of the patch and a 0.5 mm wide single complimentary split ring resonator were incorporated to achieve resonances at the desired frequencies. The dimensions of slots have been optimized to obtain the desired operation. In order to improve the return loss, three slots of equal size were etched from the lateral extremities of the patch. An upturned S shaped groove was etched to refine
Microstrip patch antennas form a viable solution for wearable antenna design as they produce omnidirectional radiation pattern and can be miniaturized by the choice of suitable substrates. The ease of fabrication and low cost add to the advantages of microstrip patch antennas [3]. In [2] authors have presented a photopaper based flexible antenna operating in 2.5GHz and 5.8 GHz frequency bands. Though photopaper is flexible and low cost but it is prone to degradation. In [4] an antenna fabricated on a felt substrate with dual band operation is proposed for on/off body wearable applications. The antenna spans the ISM and WLAN frequencies. In reference [5] authors have presented
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