scholarly journals Investigation of Flexible Textile Antennas and AMC Reflectors

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
M. Mantash ◽  
A.-C. Tarot ◽  
S. Collardey ◽  
K. Mahdjoubi
Keyword(s):  
Human Body ◽  
Monopole Antenna ◽  
Dual Band ◽  
Single Frequency ◽  
Patch Antennas ◽  
Frequency Method ◽  
Characterization Methods ◽  
Flexible Antennas ◽  
Backward Radiation ◽  
Conductive Textile

In this paper, two different methods for fabric characterization are presented: a single frequency method and a broadband method. Felt and denim fabrics are characterized, and patch antennas are designed using these substrates to test both methods. Prototypes of the antennas on felt and denim are manufactured using conductive textile (called electrotextile) aiming to obtain fully flexible antennas. The prototypes are characterized in anechoic chamber to be compared and obtain conclusions related to the characterization methods. A new dual-band hexagonal AMC reflector combinable with antennas is also proposed to improve their performance and reduce the backward radiation to the human body. A novel broadband CPW-fed monopole antenna is designed to be combined with the AMC. The resulted prototype is characterized and compared with the performance of the CPW-fed antenna alone.

scholarly journals Design and Evaluation of a Flexible Dual-Band Meander Line Monopole Antenna for On- and Off-Body Healthcare Applications

Micromachines ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 475
Author(s):  
Shahid M Ali ◽  
Cheab Sovuthy ◽  
Sima Noghanian ◽  
Zulfiqur Ali ◽  
Qammer H. Abbasi ◽  
...  
Keyword(s):  
Human Body ◽  
Impedance Matching ◽  
Ground Plane ◽  
Monopole Antenna ◽  
Dual Band ◽  
Impedance Bandwidth ◽  
Healthcare Applications ◽  
Wearable Antennas ◽  
Challenging Environment ◽  
Meander Line

The human body is an extremely challenging environment for wearable antennas due to the complex antenna-body coupling effects. In this article, a compact flexible dual-band planar meander line monopole antenna (MMA) with a truncated ground plane made of multiple layers of standard off-the-shelf materials is evaluated to validate its performance when worn by different subjects to help the designers who are shaping future complex on-/off-body wireless devices. The antenna was fabricated, and the measured results agreed well with those from the simulations. As a reference, in free-space, the antenna provided omnidirectional radiation patterns (ORP), with a wide impedance bandwidth of 1282.4 (450.5) MHz with a maximum gain of 3.03 dBi (4.85 dBi) in the lower (upper) bands. The impedance bandwidth could reach up to 688.9 MHz (500.9 MHz) and 1261.7 MHz (524.2 MHz) with the gain of 3.80 dBi (4.67 dBi) and 3.00 dBi (4.55 dBi), respectively, on the human chest and arm. The stability in results shows that this flexible antenna is sufficiently robust against the variations introduced by the human body. A maximum measured shift of 0.5 and 100 MHz in the wide impedance matching and resonance frequency was observed in both bands, respectively, while an optimal gap between the antenna and human body was maintained. This stability of the working frequency provides robustness against various conditions including bending, movement, and relatively large fabrication tolerances.

A Dual-band Monopole Antenna with EBG for Wearable Wireless Body Area Networks

2021 ◽  
Vol 36 (1) ◽  
pp. 48-54
Author(s):  
Chao Wang ◽  
Liang Zhang ◽  
Shenbing Wu ◽  
Shijie Huang ◽  
Changqing Liu ◽  
...  
Keyword(s):  
Human Body ◽  
Specific Absorption Rate ◽  
Flexible Substrate ◽  
Monopole Antenna ◽  
Dual Band ◽  
Antenna Gain ◽  
Electromagnetic Bandgap ◽  
Body Area ◽  
Body Loading ◽  
Peak Gain

This paper proposes a dual-band wearable monopole antenna adopting an electromagnetic bandgap (EBG) structure, which operates at 2.45 and 5.8 GHz ISM bands and is suitable for wearable applications. Both the monopole antenna and the EBG structure are fabricated on an F4B semi-flexible substrate having a dielectric constant of 2.2. The EBG structure effectively isolates the human body from the radiation of the antenna and reduces the specific absorption rate (SAR) of it by more than 97.5%. This improves the antenna gain and the peak gain reaches 9.1 dBi at 5.8 GHz. The wearable performance of the antenna showed that it can sustain good performance even under realistic human body loading. Besides, the antenna has a small size, which makes it ideal for wearable applications.

scholarly journals On human body transmission wearable diamond dipole antennas above engineered jackets

2021 ◽  
Vol 22 (3) ◽  
pp. 1513
Author(s):  
Muhammad Azfar Bin Abdullah ◽  
Mohamad Kamal A. Rahim ◽  
Noor Asmawati Samsuri ◽  
Mohd Fairus ◽  
Mohd Khairul Hisham Ismail ◽  
...  
Keyword(s):  
Body Mass Index ◽  
Human Body ◽  
Dipole Antenna ◽  
Coaxial Cable ◽  
Dual Band ◽  
Dipole Antennas ◽  
Flexible Antennas ◽  
Network Analyzers ◽  
Ideal Body ◽  
Antenna Placement

This paper presents the propagation of dual-band diamond dipole antenna on three various jackets. The jackets are purely fleece fabric with Shieldit fabric patches on top of it. The network analyzers with the flexible lossless coaxial cable are used to measure the communication of the antennas. The experiment involves a man with ideal body mass index (BMI) wearing the jackets by placing the flexible antennas on top of it. It is observed that the best on-body communication is by wearing the engineered jacket. The 10 dB improvements are observed when the antenna is positioned on top of engineered jacket contrast to the regular jacket. In other words, the performance of the antenna is also be determined by antenna placement. High transmission lossesses cause the antenna mismatch when the antennas are positioned above the full conductive jacket.

scholarly journals Dual-Band RF Wireless Power Transfer System with a Shared-Aperture Dual-Band Tx Array Antenna

Energies ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3803
Author(s):  
Chan-Mi Song ◽  
Hong-Jun Lim ◽  
Son Trinh-Van ◽  
Kang-Yoon Lee ◽  
Youngoo Yang ◽  
...  
Keyword(s):  
Wireless Power Transfer ◽  
Transmission Efficiency ◽  
Array Antenna ◽  
Dual Band ◽  
Single Frequency ◽  
Power Transfer ◽  
Wireless Power ◽  
Beam Focusing ◽  
Received Power ◽  
Rf Wireless

In this paper, a dual-band RF wireless power transfer (WPT) system with a shared-aperture dual-band Tx array antenna for 2.4 and 5.8 GHz is proposed. The final configuration of the Tx array, which is made up of 2.4 GHz right-handed circular polarization (RHCP) patches and 5.8 GHz RHCP patches, is derived from the optimization of 2.4 and 5.8 GHz thinned arrays, ultimately to achieve high transmission efficiency for various WPT scenarios. The dual-band RF WPT Tx system including the Tx array antenna and a Tx module is implemented, and Rx antennas with a 2.4 GHz patch, a 5.8 GHz patch, and a dual-band (2.4 and 5.8 GHz) patch are developed. To validate the proposed dual-band RF WPT system, WPT experiments using a single band and dual bands were conducted. When transmitting RF wireless power on a single frequency (either 2.482 GHz or 5.73 GHz), the received power according to the distance between the Tx and Rx and the position of the Rx was measured. When the distance was varied from 1 m to 3.9 m and the transmitted power was 40 dBm, the received power value at 2.482 GHz and 5.73 GHz were measured and found to be 24.75–13.5 dBm (WPT efficiency = 2.985–0.224%) and 19.25–6.8 dBm (WPT efficiency = 0.841–0.050%), respectively. The measured results were in good agreement with the calculated results, and it is revealed that the transmission efficiency when wireless power is transmitted via beam-focusing increases more than that with conventional beam-forming. Furthermore, the dual-band WPT experiment proves that 2.482 GHz beam and 5.73 GHz beams can be formed individually and that their wireless power can be transmitted to a dual-band Rx or two different Rx.

Sign in / Sign up

Export Citation Format

Share Document