Specific Absorption Rate Reduction Using Ebg Structure as Superstrate for Textile Antenna (original) (raw)
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Enhancement of Gain and Bandwidth using EBG Structure for Textile Antenna
International journal of applied engineering research, 2018
In this paper, Rectangular Electromagnetic Band Gap (EBG) Structure and multiple slots on patch are proposed to improve the gain and bandwidth of the Textile antenna. The EBG structure is sandwiched between the patch and the ground plane. A Single band textile antenna has a resonant frequency of 5 GHz used for IEEE802.11a Wireless Body Area Network (WBAN) applications. Four slots are created on the hexagonal patch, so the patch shape appears like WiFi symbol. For this antenna, jeans fabric is used as substrate. The design is simulated using HFSS software.
PLOS ONE, 2021
A compact fabric antenna structure integrated with electromagnetic bandgap structures (EBGs) covering the desired frequency spectrum between 2.36 GHz and 2.40 GHz for Medical Body-Area Networks (MBANs), is introduced. The needs of flexible system applications, the antenna is preferably low-profile, compact, directive, and robust to the human body's loading effect have to be satisfied. The EBGs are attractive solutions for such requirements and provide efficient performance. In contrast to earlier documented EBG backed antenna designs, the proposed EBG behaved as shielding from the antenna to the human body, reduced the size, and acted as a radiator. The EBGs reduce the frequency detuning due to the human body and decrease the back radiation, improving the antenna efficiency. The proposed antenna system has an overall dimension of 46×46×2.4 mm3. The computed and experimental results achieved a gain of 7.2 dBi, a Front to Back Ratio (FBR) of 12.2 dB, and an efficiency of 74.8%, re...
Eight Shape Electromagnetic Band Gap Structure for Bandwidth Improvement of Wearable Antenna
Progress In Electromagnetics Research C
In this paper, a rectangular eight shaped Electromagnetic Band Gap (EBG) structure at 5.8 GHz Industrial, Scientific and Medical (ISM) band for wearable application is proposed with intent to improve the impedance bandwidth of antenna. The unit cell of an EBG structure is formed using eight shape on outer ring with inner square patches. The simulation of the eight shape EBG unit cell is carried out using eigen mode solution of Ansys High Frequency Structure Simulator (HFSS). Simulated results are validated by experimental results. The application of proposed EBG for an inverse E-shape monopole antenna at 5.8 GHz is also demonstrated. Band stop property of EBG structure reduces surface waves, and therefore, the back lobe of a wearable antenna is reduced. The frequency detuning of antenna takes place due to high losses in human body. Suitably designed EBG structure reduces this undesirable effect and also improves front to back ratio. The proposed compact antenna with designed EBG has observed the impedance bandwidth of 5.60 GHz to 6.15 GHz which covers 5.8 GHz ISM band. Evaluation of antenna performance under bending condition and on-body condition is carried out. Effectiveness of EBG array structure for Specific Absorption Rate (SAR) reduction on three layer body model is demonstrated by simulations. Calculated values of SAR for tissue in 1 g and 10 g are both less than the limitations. In conclusion, it is appropriate to use the proposed antenna in wearable applications.
J-slot EBG structure for SAR Reduction of Dual Band J-slot Textile Antenna
Indonesian Journal of Electrical Engineering and Computer Science
In this article, the dual band is achieved with J-slot on rectangular Textile antenna on Jeans fabric as substrate. It resonates at the 2.4 GHz and 5.4 GHz of Wireless Body Area Network (WBAN) bands. The novel J-slot Electromagnetic Band Gap (EBG) array consists of 2x2 elements. It is used as superstrate of J-slot textile antenna for Specific Absorption Rate (SAR) reduction and gain enhancement. The Reflection coefficient and VSWR of dual band textile antenna are simulated and measured with and without human body.
Dual-Band Wearable Textile Antenna on an EBG Substrate
—Performance of a dual-band coplanar patch antenna integrated with an electromagnetic band gap substrate is described. The antenna structure is made from common clothing fabrics and operates at the 2.45 and 5 GHz wireless bands. The design of the coplanar antenna, band gap substrate, and their integration is presented. The band gap array consists of just 3 3 elements but reduces radiation into the body by over 10 dB and improves the antenna gain by 3 dB. The performance of the antenna under bending conditions and when placed on the human body are presented. Index Terms—Body-worn antennas, dual-band antennas, electromagnetic band-gap (EBG) materials, printed antennas, textile antennas.
Textile antenna incorporated with high impedance surface for on-body performance enhancement
The 8th European Conference on Antennas and Propagation (EuCAP 2014), 2014
This article presents design of a new dual band textile antenna for WiFi application. Normally available felt fabric is utilized for the design. Operating frequencies of the antenna are 2.4GHz and 5.8GHz. Designed antenna is tested in free space and in the proximity of human body model. Because of coupling with human body, the antenna performance degrades, therefore dual band high impedance surface (HIS) has been employed for minimizing these degradations. The HIS array is composed of only 9 (3x3) elements and reduces the radiations toward body and hence minimizes specific absorption rate (SAR) by 94-97 % at the operating frequencies. The integrated design is able to show improvements in return loss, gain and directivity while maintaining good impedance match with adequate bandwidth at the operating frequencies. CST Microwave Studio has been used for all the simulations and designs. .
Improving Parameters of Wearable Antenna Using EBG Structure
SINDH UNIVERSITY RESEARCH JOURNAL -SCIENCE SERIES, 2018
The wearable antenna plays a vital role in the wireless communication like Personal Area Network and Body Area Network. This is need of the hour to design a low profile, low cost, acceptable Specific Absorption Rate value, high gain, high directivity and power efficient wearable antenna for the mentioned fields of wireless communication. This paper presents an optimal solution to address the issues in the field of wearable antenna. The Electromagnetic Band Gap (EBG) structure has been integrated with the patch on the flexible substrate of polyurethane. Different parameters of wearable antenna have been improved using the EBG structure. Gain of this structure has been improved from 5.32dBi to 7.17dBi, directivity has been enhanced from 6.69dBi to 7.82dBi and efficiency has been increased from 69% to 88.87%. The results have been shown in detail in this paper.
International Journal of Numerical Modelling: Electronic Networks, Devices and Fields, 2019
In this paper, four different models of a 2.4 GHz flexible microstrip patch wearable antenna are designed and analyzed. The basic geometry of the radiating element of the antennas is a rectangular patch and is backed by conventional, mushroom-type, slotted, and spiral electromagnetic band gap (EBG) ground planes. A 3-mm-thick wash cotton textile is used as a substrate material in the design of the antennas as well as EBG surfaces. An electro-textile (Zelt) is used as a conductive material for the proposed antennas. The performance of these antennas is analyzed in terms of return loss, gain, bandwidth efficiency, and specific absorption rate (SAR) using Computer Simulation Technology Microwave Studio (CST MWS). The designed antennas are further investigated for on and off body conditions under normal and bent states. The experimental results show that the antennas radiate with an adequate gain (5.72-7.3 dB), bandwidth (65.43-103.1 MHz), and efficiency (55.51%-74.04%), depending on the type of the ground plane used. The antenna backed by the mushroom-type EBG gives the smallest value of SAR (1.79 W/kg < 2 W/kg), which makes it a suitable candidate for body worn applications in the unlicensed industrial, scientific, and medical (ISM) band.
A Low-Profile Wearable Textile Antenna Using AMC for WBAN Applications at 5.8GHz
Engineering, Technology & Applied Science Research
This paper presents a low-profile, wearable textile antenna, designed for Wireless Body Area Network (WBAN) applications operating in the 5.8GHz band for Industrial, Scientific, and Medical (ISM) applications. An Artificial Magnetic Conductor (AMC) structure was used to improve antenna performance and protect the human body from back-radiation. The antenna with the integrated AMC achieved a measured gain of 8.92dBi, an efficiency of 80%, a wide impedance bandwidth of 1.4GHz (24.1%), and SAR values of 0.00103 and 0.00034W/Kg for 10g and 1g tissues respectively. The proposed antenna was studied in a worn-on-body scenario using a multilayer numerical model of the human body. The influence of the thickness of each tissue layer of the human body was investigated. The results showed that the antenna maintained its performance, a stable gain was obtained, and the SAR values were also below the IEEE guidelines that guarantee the safety of the wearer.
A High Performance All-Textile Wearable Antenna for Wristband Application
Micromachines
A compact, conformal, all-textile wearable antenna is proposed in this paper for the 2.45 GHz ISM (Industrial, Scientific and Medical) band. The integrated design consists of a monopole radiator backed by a 2 × 1 Electromagnetic Band Gap (EBG) array, resulting in a small form factor suitable for wristband applications. An EBG unit cell is optimized to work in the desired operating band, the results of which are further explored to achieve bandwidth maximization via floating EBG ground. A monopole radiator is made to work in association with the EBG layer to produce the resonance in the ISM band with plausible radiation characteristics. The fabricated design is tested for free space performance analysis and subjected to human body loading. The proposed antenna design achieves bandwidth of 2.39 GHz to 2.54 GHz with a compact footprint of 35.4 × 82.4 mm2. The experimental investigations reveal that the reported design adequately retains its performance while operating in close proximit...