Performance Of Textile Antenna Research Articles

Dual-resonance ultra-miniaturised textile antenna for ISM/wearable applications

ABSTRACT In this paper, an ultra-miniaturised textile antenna is designed and developed for 2.45/5.8 GHz industrial, scientific and medical (ISM) band applications. The proposed microstrip line-fed dual-band antenna consists of non-conducting (Felt) and conducting (Sheildit Super) textile materials. The size of the antenna is 20 mm×30 mm×1 mm, and its (S11≤–10) bandwidths in the lower and upper resonant bands are 14.2% and 27.5%, respectively. In addition, various fabrics are considered and characterised in order to investigate different possibilities for textile antennas. The proposed antenna configuration is simple, compact, easy to manufacture, and efficient for wearable/textile applications. The proposed textile antenna performance is studied for on-body situations using the three-layered human shoulder model and four-layered human arm model. The antenna offers consistent on-body performance even when subjected to deformations caused by bending.

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

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.

Design and on-body evaluations of a low-cost wearable PIFA for on-body applications

A flexible low profile textile antenna based on planar inverted-F antenna (PIFA) structure is presented in this paper. This topology has been chosen due to its design simplicity, relatively large bandwidth and the existence of a full rear ground plane, which shields against the effects of the body. The antenna topology which is designed on a 4 mm-thick felt substrate is presented. Conductive textile (Aaronia-shield) is applied as the antenna’s radiator and ground plane due to its light weight, low surface resistance and good conductivity. The antenna performance in free space and bent conditions in the proximity of human body are studied, followed by a numerical investigation on the influence of relative humidity on the textile antenna performance. The fabricated PIFA is assessed experimentally and is found to be in good agreements with the simulation results. Finally, the antenna is attached to a compact RF module and is evaluated on body in a practical environment. The wireless link quality is also evaluated in an indoor laboratory environment.

A Machine-Learning-Based Epistemic Modeling Framework for Textile Antenna Design

A novel machine-learning-based framework to evaluate the effect of design parameters affected by epistemic uncertainty on the performance of textile antennas is presented in this letter. In particular, epistemic variations are characterized in the framework of possibility theory, which is combined with Bayesian optimization to accurately and efficiently perform uncertainty quantification. A suitable application example validates the proposed method.

Durability testing of electronic textile surface resistivity and textile antenna performance

As wearable electronics become more prevalent in everyday life, there is a growing desire to integrate circuits and antennae into clothing. One way that this integration may occur is through use of electronic textiles (e-textiles). However, changes in environmental and wear conditions may affect the conductive data communication performance of the e-textile, such as surface resistivity and antenna radiation characteristics. In this study, the effects of pilling, wrinkling, abrasion, and laundering of e-textiles were examined for resistivity performance. E-textile resistivity performance from both direct current (DC) and radiofrequency (RF) perspectives were measured following AATCC and ASTM standards. For DC performance, results indicate that pilling causes severe damage to e-textile resistivity, while laundering and wrinkling did not substantially affect e-textile resistivity performance. For RF performance in this study, an e-textile microstrip patch antenna was designed and data were collected under similar environmental and wear conditions. RF performance change corresponds with DC performance change. The findings of this paper highlight limitations of the evaluated e-textile performance, and provide new perspectives regarding improvements to e-textile fabrication for sustaining performance through environmental and wear operations.

Design and Performance of Textile Antenna for Wearable Applications

In this paper, a novel co-planar waveguide fed textile antenna is to be designed for wearable applications. The designed antenna has the design parameters of the size is 90 mm × 70 mm × 1.57 mm3 and the substrate is Jeans cloth whose dielectric constant is 1.6. The proposed antenna resonates at 2.45 GHz with a return loss of − 19 dB. The proposed antenna has a gain of 2 dBi and VSWR is around 1.1 at the resonating frequency. This logo shaped antenna can be radically used in military jackets, because of its compatibility, flexibility in structure design and shape, excellent performance at different angles, human safety, miniaturization, power consumption etc.

Stochastic Analysis of the Impact of Substrate Compression on the Performance of Textile Antennas

One of the many adverse effects modifying the performance of textile antennas in real operating conditions is substrate compression. Therefore, this communication presents a stochastic collocation method (SCM) that either relies on the generalized polynomial chaos (gPC) expansion or on a novel Hermite-Pade approximant. The method is introduced to rigorously quantify the effect of random variations in the height and the permittivity of the substrate on the figures of merit of a textile antenna. Next, the joint height and permittivity probability distribution of a compressible substrate are characterized by means of a new measurement setup based on a resonant-perturbation technique. Finally, the method is validated for a probe-fed GPS textile antenna. It is shown that Hermite-Pade approximants model the highly nonlinear relationship between these substrate random variables and the figures of merit of the antenna more efficiently than the gPC. Moreover, a Kolmogorov–Smirnoff test proves that the resulting distributions of the antenna’s figures of merit are as accurate as those obtained by means of a Monte-Carlo (MC) analysis, with demonstrated speedup factors up to 123.

A Stochastic Framework for the Variability Analysis of Textile Antennas

A novel framework to accurately quantify the effect of stochastic variations of design parameters on the performance of textile antennas is developed and tested. First, a sensitivity analysis is applied to get a rough idea about the effect of these random variations on the textile antenna's performance. Next, a more detailed view is obtained by a generalized polynomial chaos technique that accurately quantifies the statistical distribution of the textile antenna's figures of merit, for a given range over which geometry and material parameters vary statistically according to a given distribution. The method is validated both for a simple inset-fed patch textile microstrip antenna and for a dual-polarized textile antenna. For the latter, the probability density function corresponding to its most sensitive design parameter, being the width, is experimentally estimated by means of measurements performed on 100 patches. A Kolmogorov-Smirnoff test proves that, for all considered examples, the results are as accurate as those obtained via Monte Carlo analysis, while the new technique is much more efficient. Indeed, speedups up to a factor 1667 are demonstrated.

Textile Antennas as Hybrid Energy-Harvesting Platforms

Smart-fabric interactive-textile systems offer exciting new possibilities, provided that they exhibit sufficient robustness and autonomy to be reliably deployed in critical applications. Textile multiantenna systems, unobtrusively integrated in a professional garment, are key components of such systems, as they set up energy-efficient and stable wireless body-centric communication links. Yet, their functionality may be further extended by exploiting their surface as energy-harvesting platform. Different state-of-the-art energy harvesters are suitable for compact integration onto a textile antenna. We demonstrate this by integrating a power management system, together with multiple diverse scavenging transducers and a storage module, on a well-chosen textile antenna topology. We provide guidelines to ensure that the additional hardware does not affect the textile antenna's performance. Simultaneous scavenging from different energy sources significantly increases the autonomy of a wearable system, in the meanwhile reducing battery size.

NUMERICAL AND EXPERIMENTAL ANALYSIS OF WIDEBAND E-SHAPE PATCH TEXTILE ANTENNA

In this paper, we present a wideband planar E- shaped textile antenna and study its performance numerically and experimentally. The textile material and radiation patch shape provide the antenna a wide working band (2.25GHz{2.75GHz). A digital human model is established to numerically analyze the afiect of human body on antenna. Experiments are carried out to study the performance changes of antenna in difierent states which may be experienced in the potential applications. These states are antenna on human body, antenna getting bent, and antenna after getting wet. The simulated and measured results in free space and on human chest show good agreement with each other. From the study it is also found that the textile antenna's performance does not get deteriorated in these states. Therefore, the wideband planar E-shaped textile antenna is suitable for body-centric wireless communications with high quality.

Influence of Relative Humidity on Textile Antenna Performance

The next generation of garments is sensorized, and therefore requires an adapted wireless communication tool such as a textile antenna. However, when integrating this flexible antenna into clothing, stable and reliable functioning in the operating frequency range is required. Climatic changes, especially altering relative humidity, might influence the textile antenna performance. This effect has to be taken into consideration when selecting the textile materials that comprise the antenna. A variety of antenna substrate materials has been investigated in this paper. It was found that antennas based on materials with a small moisture regain (less than 3 %) provided a more stable antenna characteristic, and can therefore preferably be applied as antenna substrate.