Recent Advances in Wearable Antenna Technologies: A Review

Abstract

Wearable antennas have received a great deal of popularity in recent years owing to their enticing characteristics and opportunities to realize lightweight, compact, low-cost, and versatile wireless communications and environments. These antennas must be conformal, and they must be built using lightweight materials and constructed in a low-profile configuration when mounted on various areas of the human body. These antennas ought to be able to function close to the human body with limited deterioration. These criteria render the layout of wearable antennas demanding, particularly when considering factors such as investigating the usability of textile substrates, high conductive materials during fabrication processes, and the effect of body binding scenarios on the performance of the design. Although there are minor differences in magnitude based on the implementations, several of these problems occur in the body-worn deployment sense. This study addresses the numerous problems and obstacles in the production of wearable antennas, their variety of materials, and the techniques of manufacturing alongside with bending scheme. This is accompanied by a summary of creative features and their respective approaches to address these problems recently raised by work in this area by the science community.

Textile Slotted Waveguide Antennas for Body-Centric Applications

“…To fulfill their task, textile antennas should resemble common textile materials in flexibility, lightweight, and aesthetics yet show good radiation efficiency and impedance matching, mechanical durability, water resistance, etc., as well as allow implementation of technologies such as Multiple-Input Multiple-Output (MIMO) [ 5 , 6 , 7 , 8 , 9 , 10 , 11 ]. As textile antennas are designed to operate on the human (user’s) body, another important requirement are maximum exposure limits to electromagnetic (EM) fields, i.e., maximum Specific Absorption Rate (SAR), which should not be exceeded [ 12 , 13 , 14 ].…”

“…While the vast majority of existing textile antennas are dipoles, monopoles, Planar Inverted-Fs (PIFAs), microstrip patches, and planar antennas in general, which are of a low profile and can be used on a variety of curved surfaces [ 7 , 8 , 15 ], there are still unexplored possibilities of adapting other types of common antennas to be realized as textile ones and adapted for wearable application. The aim of this paper is to explore properties of a textile slotted waveguide antenna array [ 16 ] that could easily be attached to a jacket, vest, belt, or another article of clothing.…”

Three‐dimensional star antenna for wearable defense application

“…Many antenna structures have been proposed and reported by various researchers for achieving an efficient communication in the requisite radio frequency bands. 1 Among them, the most common antennas are microstrip patch, 2,3 printed dipole and monopole, 4,5 printed loop, 6,7 slot antennas, 8,9 and planar inverted F-antenna. 10,11 Moreover, mounting of antenna on certain positions over the body, such as wrist, helmet, and so on, requires the antenna to have flexible characteristics 12,13 whereas for positions like shoulder, chest, and so on, low profile miniature rigid antenna may be used.…”

“…Development of wearable technology has been emerging rapidly nowadays where most of the applications use miniature antennas mounted on different positions of human body for exchanging data wirelessly. Many antenna structures have been proposed and reported by various researchers for achieving an efficient communication in the requisite radio frequency bands 1 . Among them, the most common antennas are microstrip patch, 2,3 printed dipole and monopole, 4,5 printed loop, 6,7 slot antennas, 8,9 and planar inverted F‐antenna 10,11 .…”

The effects of material’s features and feeding mechanism on high-gain antenna construction

“…As a result, using UWB antennas to obtain high-resolution photos is recommended [28], [30]- [35]. Besides, for lightweight high-gain antennas devoted to portable and wearable devices [36], there is a significant basic necessity and high demand. Given their compact sizes and the high gain values that influence the efficiency of the realized signal, this study is organized to describe and differentiate several types of flexible antennas.…”