scholarly journals Evaluation of a Textile PIFA for Wearable IoT Application and its Challenges

2021 ◽  
Vol 15 (3) ◽  
pp. 289-302
Author(s):  
Hadi Aliakbarian ◽  
Azadeh Hajiahmadi ◽  
Nordiana Mohamad Saaid ◽  
Ping Jack Soh
Keyword(s):  
Human Body ◽  
Ground Plane ◽  
The Body ◽  
Link Quality ◽  
Test Case ◽  
Antenna Performance ◽  
Textile Antenna ◽  
Close Proximity ◽  
Transceiver Module ◽  
Conductive Textile

The ever increasing use of body-worn systems in the Internet of Things application such as needs better antenna subsystem designs compatible with its requirements. Several challenges limiting the performance of a body-worn system, from materials, and environmental conditions  to the effects of on body application and its hazards are discussed. As a test case, a flexible textile planar inverted-F antenna is presented and discussed. The choice of this topology is due to its simplicity in design and fabrication, relatively broad bandwidth and the presence of a rear ground plane, which minimizes the impacts of the human body on the antenna performance. It is designed on a felt substrate, whereas Aaronia-shield conductive textile is utilized as its  conductive parts (radiator, shorting wall and ground plane). The antenna performance are studied in two cases, first in free space and then in bent conditions in the close proximity to the human body. The influence of the relative humidity on the textile antenna performance is also investigated numerically. Simulated and measured results indicated good agreements. Finally, the proposed antenna is integrated with a transceiver module and evaluated on the body in practice. Its wireless link quality is assessed in an indoor laboratory.

Redesign of an Adjustable Slope Moving Ground Plane Wind Tunnel

2011 ◽  
Author(s):  
Matthew T. Boots ◽  
Meagan L. Hubbell ◽  
Gerald M. Angle ◽  
Emily D. Pertl ◽  
James E. Smith
Keyword(s):  
Wind Tunnel ◽  
Test Section ◽  
Ground Plane ◽  
Ground Effect ◽  
The Body ◽  
Original Design ◽  
Local Pressure ◽  
Maximum Angle ◽  
Close Proximity ◽  
Base Structure

Ground effect is an aerodynamic phenomenon that occurs when moving bodies come in close proximity to the ground. A “cushion” of air is created underneath the moving body which provides additional lift by increasing the local pressure under the body surface. To experimentally test ground effect vehicles, a unique wind tunnel is currently being redesigned and constructed at West Virginia University. This wind tunnel incorporates a rotating belt as the ground plane and a centrifugal fan that generates the air flow through the test section in the same direction as the belt’s rotation. The combination of a rotating belt and airflow is used to mimic ground effect in that it is representative of a body moving through still air in close proximity to the ground. The test section and fan assembly sit on a platform that is connected to a movable base frame. The base and testing platform connect through a pivot point that is capable of being raised upward to a maximum angle of fifty degrees to account for gravitational vector alignment between modeled and real world conditions. When the platform is raised and the belt is spinning, the structure is less stable and has the potential to create errors in force readings due to these oscillations, as well as the potential to tip in extreme wind conditions. Thus, the evaluation of the original design and the subsequent redesign are addressed in this research effort. To stabilize the wind tunnel, additional structural elements have been added downstream of the test section. Two telescoping poles were added to the end of the platform that will connect onto outriggers attached to the base structure. These poles and outriggers will form an A-shape support system when the platform is raised to any degree between zero and fifty. The width of the outriggers was calculated and then modeled in conjunction with the existing base structure. The final design is presented in this paper.

scholarly journals Analysis on the Effects of the Human Body on the Performance of Electro-Textile Antennas for Wearable Monitoring and Tracking Application

Materials ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 1636 ◽  
Author(s):  
Nurul Huda Abd Rahman ◽  
Yoshihide Yamada ◽  
Muhammad Shakir Amin Nordin
Keyword(s):  
Human Body ◽  
Free Space ◽  
Dielectric Material ◽  
Near Field ◽  
The Body ◽  
Antenna Structure ◽  
Dielectric Characteristics ◽  
Wearable Antennas ◽  
Close Proximity ◽  
Substantial Drop

Previous works have shown that wearable antennas can operate ideally in free space; however, degradation in performance, specifically in terms of frequency shifts and efficiency was observed when an antenna structure was in close proximity to the human body. These issues have been highlighted many times yet, systematic and numerical analysis on how the dielectric characteristics may affect the technical behavior of the antenna has not been discussed in detail. In this paper, a wearable antenna, developed from a new electro-textile material has been designed, and the step-by-step manufacturing process is presented. Through analysis of the frequency detuning effect, the on-body behavior of the antenna is evaluated by focusing on quantifying the changes of its input impedance and near-field distribution caused by the presence of lossy dielectric material. When the antenna is attached to the top of the body fat phantom, there is an increase of 17% in impedance, followed by 19% for the muscle phantom and 20% for the blood phantom. These phenomena correlate with the electric field intensities (V/m) observed closely at the antenna through various layers of mediums (z-axis) and along antenna edges (y-axis), which have shown significant increments of 29.7% in fat, 35.3% in muscle and 36.1% in blood as compared to free space. This scenario has consequently shown that a significant amount of energy is absorbed in the phantoms instead of radiated to the air which has caused a substantial drop in efficiency and gain. Performance verification is also demonstrated by using a fabricated human muscle phantom, with a dielectric constant of 48, loss tangent of 0.29 and conductivity of 1.22 S/m.

scholarly journals Planar MIMO Antenna with Slits for WBAN Applications

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Do-Gu Kang ◽  
Jinpil Tak ◽  
Jaehoon Choi
Keyword(s):  
Resonant Frequency ◽  
Human Body ◽  
Impedance Matching ◽  
Ground Plane ◽  
Antenna Size ◽  
Mimo Antenna ◽  
Ism Band ◽  
Antenna Performance

A planar MIMO antenna with slits for WBAN applications is proposed. The antenna consists of two PIFAs, ground pads, and two slits. By adding ground pads, the antenna size is reduced with improved impedance matching. Through two slits in a ground plane, the isolation characteristic is improved and the resonant frequency can be controlled. To analyze the antenna performance on a human body, the proposed antenna on a human equivalent flat phantom is investigated through simulations. Regardless of the existence of the phantom, the antenna operates in 2.4 GHz ISM band with the isolation higher than 18 dB.

scholarly journals Miniaturization and Electromagnetic Reliability of Wearable Textile Antennas

Electronics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 994
Author(s):  
Lan Yao ◽  
Erhong Li ◽  
Jiangshan Yan ◽  
Zhiyong Shan ◽  
Xinyi Ruan ◽  
...  
Keyword(s):  
Microstrip Antenna ◽  
Screen Printing ◽  
Decisive Role ◽  
The Body ◽  
Screen Printing Method ◽  
Wireless Communication Network ◽  
Antenna Performance ◽  
Textile Antenna ◽  
Backward Radiation ◽  
Performance Results

The wearable textile antenna plays a decisive role in the currently increasingly wireless communication network area. To realize the miniaturization and electromagnetic reliability, a slotted full-textile microstrip antenna was designed and fabricated using the screen printing method. The measured return loss and radiation pattern were tested and compared with the simulated results. Additionally, the adhesion between the silver paste coating as the radiation element and the textile substrate was detected using sticking tape as well as observation by the microscope. To develop the designed antenna in the on-body application, the artificial magnetic conductor (AMC) was designed, optimized and fabricated. The antenna performance results showed that the existence of the AMC had a significant effect in reducing the body coupling and antenna backward radiation.

scholarly journals Compact Microstrip-Based Textile Antenna for 802.15.6 WBAN-UWB with Full Ground Plane

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
Author(s):  
Purna B. Samal ◽  
Ping Jack Soh ◽  
Zahriladha Zakaria
Keyword(s):  
Ground Plane ◽  
Wireless Body Area Network ◽  
Federal Communications Commission ◽  
The Body ◽  
Area Network ◽  
Uwb Antenna ◽  
Microstrip Patch ◽  
Textile Antenna ◽  
Compact Size ◽  
High Band

The paper presents the design and investigation of a flexible all-textile antenna operating in the wireless body area network (WBAN) ultrawideband (UWB) specified by the IEEE 802.15.6 standard. The proposed antenna features an innovative and compact UWB radiator on top of the overall structure with a full ground plane on its reverse side. The radiator, which is based on a microstrip patch combined with multiple miniaturization and broadbanding methods, resulted in a simple topology and a compact size of 39 mm×42 mm×3.34 mm (0.51×0.55×0.043λ). In comparison to the literature, the proposed structure is considered to be the most compact microstrip-based textile UWB antenna to date featuring a full ground plane. The choice of the commercial textiles is also made based on cost efficiency, ease of accessibility, and ease of fabrication using simple tools. Meanwhile, the full ground plane enables the antenna operation in the vicinity of the human body with minimal body coupling and radiation towards it, ensuring operational safety. Besides its operation in the mandatory channels of the WBAN-UWB low and high bands, the proposed antenna also operates and preserves its performance in five other optional channels of the high band when placed on the body and under bend conditions of 30° and 60°. The proposed antenna successfully achieved the specific absorption rate below the regulated limit specified by the Federal Communications Commission.

scholarly journals FRACTAL KOCH MULTIBAND TEXTILE ANTENNA PERFORMANCE WITH BENDING, WET CONDITIONS AND ON THE HUMAN BODY

2013 ◽  
Vol 140 ◽  
pp. 633-652 ◽  
Author(s):  
Mohd Ezwan Bin Jalil ◽  
Mohamad Kamal Abd Rahim ◽  
Noor Asmawati Samsuri ◽  
Noor Asniza Murad ◽  
Huda Abdul Majid ◽  
...  
Keyword(s):  
Human Body ◽  
Antenna Performance ◽  
Textile Antenna

TEXTILE DIPOLE ANTENNA FOR WEARABLE APPLICATION

2015 ◽  
Vol 77 (1) ◽  
Author(s):  
M. A. Abdullah ◽  
Mohamad Kamal A. Rahim ◽  
N. A. Samsuri ◽  
N. A. Murad ◽  
M. E. Jalil
Keyword(s):  
Human Body ◽  
Electronic System ◽  
Dipole Antenna ◽  
The Body ◽  
Antenna Measurement ◽  
Wearable System ◽  
Antenna Performance ◽  
System A ◽  
Conducting Materials ◽  
Wet Condition

 The idea of wearable electronic system has triggered a vast research on the capability of implementing the system on daily garment. As a wearable system, the human body friction should be taken into account. Antenna is one of the main structure in wearable communication system. This paper presents a study on a textile dipole antenna with two different conducting materials. The conducting materials are Shieldit fabric and copper fabric while the substrate is denim. The denim has a dielectric constant of 1.67 with 0.85 mm thickness and loss tangent of 0.019. The antenna resonates at Industrial, Scientific, and Medical (ISM) band which is at 2.45 GHz. Antenna performances are observed in terms of reflection coefficient, bandwidth, and radiation pattern. Three different investigations are analysed: antenna measurement with two different bending sizes, under wet conditions and on-body conditions. The bending and wetness effect of the textile antenna are also investigated. No significant changes to the antenna performance under the bending condition. The antenna cannot operate in wet condition at desired frequency. In addition, on-body measurement is done to investigate the antenna properties in wearable system. A suitable placement of the antenna on the human body has been discovered between the front and back of the body and the arm.

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