Impact of Electromagnetic Properties of Textile Materials on Performance of a Low-Profile Wearable Antenna Backed by a Reflector

2020 ◽  
Author(s):  
Gabriela L. Atanasova ◽  
Nikolay T. Atanasov
Keyword(s):  
Electromagnetic Properties ◽  
Textile Materials ◽  
Wearable Antenna ◽  
Low Profile

scholarly journals Small Antennas for Wearable Sensor Networks: Impact of the Electromagnetic Properties of the Textiles on Antenna Performance

Sensors ◽  
2020 ◽  
Vol 20 (18) ◽  
pp. 5157
Author(s):  
Gabriela Atanasova ◽  
Nikolay Atanasov
Keyword(s):  
Sensor Networks ◽  
Loss Tangent ◽  
Rapid Development ◽  
Substrate Material ◽  
Radiation Efficiency ◽  
Electromagnetic Properties ◽  
Textile Materials ◽  
Antenna Performance ◽  
Low Profile ◽  
The Impact

The rapid development of wearable wireless sensor networks (W-WSNs) has created high demand for small and flexible antennas. In this paper, we present small, flexible, low-profile, light-weight all-textile antennas for application in W-WSNs and investigate the impact of the textile materials on the antenna performance. A step-by-step procedure for design, fabrication and measurement of small wearable backed antennas for application in W-WSNs is also suggested. Based on the procedure, an antenna on a denim substrate is designed as a benchmark. It demonstrates very small dimensions and a low-profile, all while achieving a bandwidth (|S11| < −6 dB) of 285 MHz from 2.266 to 2.551 GHz, radiation efficiency more than 12% in free space and more than 6% on the phantom. Also, the peak 10 g average SAR is 0.15 W/kg. The performance of the prototype of the proposed antenna was also evaluated using an active test. To investigate the impact of the textile materials on the antenna performance, the antenna geometry was studied on cotton, polyamide-elastane and polyester substrates. It has been observed that the lower the loss tangent of the substrate material, the narrower the bandwidth. Moreover, the higher the loss tangent of the substrate, the lower the radiation efficiency and SAR.

scholarly journals Wearable Textile Antennas with High Body-Antenna Isolation: Design, Fabrication, and Characterization Aspects

2020 ◽  
Author(s):  
Nikolay Atanasov ◽  
Gabriela Atanasova ◽  
Blagovest Atanasov
Keyword(s):  
Resonant Frequency ◽  
Human Body ◽  
Detailed Examination ◽  
Electromagnetic Properties ◽  
Trade Off ◽  
High Body ◽  
Wearable Antennas ◽  
Low Profile ◽  
Design Requirements

This chapter provides a brief overview of the types of wearable antennas with high body-antenna isolation. The main parameters and characteristics of wearable antennas and their design requirements are discussed. Next, procedures (passive and active) to test the performance of wearable antennas are presented. The electromagnetic properties of the commercially available textiles used as antenna substrates are investigated and summarized here, followed by a more detailed examination of their effects on the performance of wearable antennas with high body-antenna isolation. A trade-off between substrate electromagnetic properties and resonant frequency, bandwidth, radiation efficiency, and maximum gain is presented. Finally, a case study is presented with detailed analyses and investigations of the low-profile all-textile wearable antennas with high body-antenna isolation and low SAR. Their interaction with a semisolid homogeneous human body phantom is discussed. The simulations and experimental results from different (in free-space and on-body) scenarios are presented.

scholarly journals Experimental Research on Textile and Non-Textile Materials with Applications to Ensure Electromagnetic and Bio-Electromagnetic Compatibility

2019 ◽  
Vol 25 (3) ◽  
pp. 13-18
Author(s):  
Octavian Baltag ◽  
Alina Lacrămioara Apreutesei ◽  
Georgiana Roșu ◽  
George Mihai
Keyword(s):  
Composite Structures ◽  
Electromagnetic Compatibility ◽  
Metal Structure ◽  
Cellular Systems ◽  
Electromagnetic Properties ◽  
Carbon Powder ◽  
Textile Materials ◽  
Properties And Characterization ◽  
Functional Textiles

Abstract The paper presents a synthesis of the research performed on the electromagnetic properties and characterization of textile and non-textile materials with applications in shielding and protection from the electromagnetic field. The composite structures of functional textiles intended for protective clothing or general applications for electromagnetic immunity are presented and characterized. There are analyzed composite textiles with amorphous, ferrous or non-ferromagnetic metallic threads manufactured by means of woven and knitting classical technologies as well as materials using non-metallic, electrically conductive powders. The properties of the plain jersey, rib jersey, full and half cardigan fabric, Milano rib, are presented, too. Besides textiles, there are also characterized some composite and non-composite structures using metallic yarns and carbon powder. Another direction of interest relates to the use of textile materials with amorphous metal structure with the scope of achieving a more efficient protection to the electromagnetic fields used in cellular systems and Wi-Fi networks. In addition, a comparative analysis of the methods of characterization of composite structures is made.

scholarly journals Design and Electromagnetic Properties of a Conformal Ultra Wideband Antenna Integrated in Three-Dimensional Woven Fabrics

Polymers ◽  
2018 ◽  
Vol 10 (8) ◽  
pp. 861 ◽  
Author(s):  
Ye Kuang ◽  
Lan Yao ◽  
Sheng-Hai Yu ◽  
Shuo Tan ◽  
Xiu-Jun Fan ◽  
...  
Keyword(s):  
Printed Circuit Board ◽  
Three Dimensional ◽  
Life Quality ◽  
Woven Fabrics ◽  
Ultra Wideband ◽  
Circuit Board ◽  
Woven Fabric ◽  
Electromagnetic Properties ◽  
Textile Materials ◽  
High Data

Wearable antennas play an important role in transmitting signals wirelessly in body-worn systems, helping body-worn applications to achieve real-time monitoring and improving the working efficiency as well as the life quality of the users. Over conventional antenna types, ultra wideband (UWB) antennas have advantages of very large operating bandwidth, low power consumption, and high data transmission speed, therefore, they become of great interest for body-worn applications. One of the strategies for making the antenna comfortable to wear is replacing the conventional rigid printed circuit board with textile materials in the manufacturing process. In this study, a novel three-dimensional woven fabric integrated UWB antenna was proposed and fabricated with pure textile materials. The antenna electromagnetic properties were simulated and measured and its properties under bending were investigated. The antenna operated in a wide bandwidth from 2.7 to 13 GHz with the proper radiation pattern and gain value. At the same time, the antenna performance under bending varied in a reasonable range indicating that the antenna is prospectively applied on the curved surfaces of the human body. Additionally, the current distribution of the antenna showed that different conductive parts had different current densities indicating the uniqueness of the three-dimensional textile-based antenna.

scholarly journals A Low-Profile Ultrawideband Antenna Based on Flexible Graphite Films for On-Body Wearable Applications

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4526
Author(s):  
Wenhua Li ◽  
Haoran Zu ◽  
Jinjin Liu ◽  
Bian Wu
Keyword(s):  
Corrosion Resistance ◽  
Horizontal Plane ◽  
Impedance Matching ◽  
Wearable Devices ◽  
Light Weight ◽  
Suitable Candidate ◽  
Wearable Antenna ◽  
Low Profile ◽  
Flexible Graphite ◽  
Good Agreement

This paper presents a low-profile ultrawideband antenna for on-body wearable applications. The proposed antenna is based on highly conductive flexible graphite films (FGF) and polyimide (PI) substrate, which exhibits good benefits such as flexibility, light weight and corrosion resistance compared with traditional materials. By introducing flaring ground and an arrow-shaped slot, better impedance matching is achieved. The wearable antenna achieves a bandwidth of 122% from 0.34 GHz to 1.4 GHz, with a reflection coefficient of less than −10 dB, while exhibiting an omnidirectional pattern in the horizontal plane. To validate the proposed design, the wearable antenna with a profile of ~0.1 mm was fabricated and measured. The measured results are in good agreement with simulated ones, which indicates a suitable candidate for on-body wearable devices.

Influence of some structural parameters on the dielectric behavior of materials for textile antennas

2018 ◽  
Vol 89 (7) ◽  
pp. 1131-1143 ◽  
Author(s):  
Caroline Loss ◽  
Ricardo Gonçalves ◽  
Pedro Pinho ◽  
Rita Salvado
Keyword(s):  
Surface Roughness ◽  
Dielectric Material ◽  
Structural Parameters ◽  
Microstrip Antennas ◽  
Dielectric Behavior ◽  
Electromagnetic Properties ◽  
Textile Materials ◽  
Dielectric Characterization ◽  
Wearable Antennas ◽  
Constant E

Knowledge of the electromagnetic properties of textile materials is crucial in order to design wearable antennas. Despite the growth of research studies on textile antennas, the accurate characterization of the dielectric properties of the materials is still a challenge due to the intrinsic inhomogeneity and deformability of textiles. In this work, 11 textile materials were characterized using the resonator-based experimental technique. The results obtained using this method have shown that when positioning the roughest face of the Material Under Test (MUT) in contact with the resonator board, the extracted dielectric constant (ɛ r) value is lower than the one extracted with this face positioned upside-down. Based on this observation, superficial properties of textiles were investigated. Thus, this paper relates the results of the dielectric characterization to some structural parameters of textiles, such as surface roughness and surface and bulk porosity. The results show that both surface roughness and surface porosity of the samples influence the measurements, through the positioning of the probes. Further, the influence of the positioning of the dielectric material on the performance of textile microstrip antennas was analyzed. For this, 12 prototypes of microstrip patch antennas were developed and tested. The results show that, despite the differences obtained in the characterization when placing the face or reverse-sides of the MUT in contact with the resonator board, the obtained average result of ɛ r is well suited to design antennas, ensuring a good performance.

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