Wearable Button Antenna Research Articles

Fractal slot loaded compact wearable button antenna for IOT and X-band applications

Fractal slot loaded compact wearable button antenna for IOT and X-band applications

A Wearable Button Antenna Sensor for Dual-Mode Wireless Information and Power Transfer.

A novel wearable button antenna sensor is proposed for the concept of simultaneous wireless information and power transfer (SWIPT). This integrates two working modes for the transfer of power and information, respectively, and optimizes transfer efficiency. An omni-directional radiation pattern is achieved in the 3.5 GHz World Interoperability for Microwave Access (WiMAX) band to support on-body wireless communications, while a circularly polarized broadside radiation pattern is obtained in the 5 GHz wireless local area networks (WLAN) band to harvest power. The measured −10 dB return loss bandwidths are 4.0% (3.47–3.61 GHz) in the lower band, and 25.0% (4.51–5.80 GHz) in the higher band, respectively. An artificial magnetic conductor (AMC) structure with wideband characteristics is applied to obtain a low-profile design and to increase the stability of the antenna sensor. A high radiation efficiency of over 80% in the whole working band is observed. The specific absorption rate (SAR) of the proposed antenna sensor is below 0.509 W/kg at 3.55 GHz, and below 0.0532 W/kg at 5.5 GHz, respectively, which is much lower than the European standard threshold of 2 W/kg. All these characteristics make the designed antenna sensor suitable for on-body information transmission and off-body energy harvesting. The antenna sensor has been prototyped. Simulations and measurements agree well, proving the validity of the new concept.

Omni-Directional Circularly Polarized Button Antenna for 5 GHz WBAN Applications

An omni-directional circularly polarized wearable antenna for 5 GHz applications is proposed. The antenna is constructed on a button-like setup, using the concept of a magnetic dipole combined with a flexible patch located on a textile substrate to optimize the antenna performance. With the proposed topology, an omni-directional pattern involving a robust circular polarization (CP) for on-body communication is reached. The -10 dB impedance bandwidth ranges from 5.68 to 5.91 GHz. The 3 dB axial ratio bandwidth ranges from 5.72 to 5.9 GHz. The omni-directional pattern is ideal for indoors and the CP is able to cope with any possible polarization mismatch caused by human body motions. Comparing with literature, this antenna takes the special case of wearable applications into account, which makes it the first practical wearable button antenna that features an omni-directional radiation pattern featuring CP.

Compact Circularly Polarized Wearable Button Antenna With Broadside Pattern for U-NII Worldwide Band Applications

A novel circularly polarized button antenna is proposed. The antenna is constructed on a disk-shaped FR-4 substrate. This disk is located on the top of a textile layer and supported by a feeding probe. The antenna works in the 5.47-5.725 GHz Unlicensed National Information Infrastructure worldwide band, with over 14% relative impedance bandwidth and over 7% relative axial ratio bandwidth. A prototype has been fabricated and measured. A good agreement is found between measured and simulated results.

Design of Wideband Button Antenna Based on Characteristic Mode Theory.

A wideband wearable button antenna working around 2.4GHz is proposed in this paper. The function of the textile antenna ground is analyzed based on characteristic mode theory. By properly locating the button on the ground, the latter can be efficiently excited and operates as a radiator. This is shown to greatly increase the impedance bandwidth. The antenna is analyzed both in free space and on the human body. A prototype is fabricated, and the measured results agree satisfactorily with the simulations. In free space, the bandwidth, the realized gain, and radiation efficiency are 658MHz, 1.8dBi, and 97%, respectively. While on the human body, the values can reach 788MHz, 5.1dBi, and 71%, respectively. This wide band behavior provides robustness across different environments and to relatively large fabrication tolerances. The specific absorption rate is below 0.45W/kg for an equivalent isotropically radiated power of 20dBm.

Wearable Button Antenna for Dual-Band WLAN Applications With Combined on and off-Body Radiation Patterns

A new type of wearable button antenna for wireless local area network (WLAN) applications is proposed. The antenna is composed of a button with a diameter of circa 16 mm incorporating a patch on top of a dielectric disc. The button is located on top of a textile substrate and a conductive textile ground that are to be incorporated in clothing. The main characteristic feature of this antenna is that it shows two different types of radiation patterns, a monopole type pattern in the 2.4 GHz band for on-body communications and a broadside type pattern in the 5 GHz band for off-body communications. A very high efficiency of about 90% is obtained, which is much higher than similar full textile solutions in the literature. A prototype has been fabricated and measured. The effect of several real-life situations such as a tilted button and bending of the textile ground have been studied. Measurements agree very well with simulations.

G-Shaped Dual Band Wearable Button Antenna for ISM Band Applications

Performance of a dual-band wearable button antenna is presented. The designed radiation structure has a metallic G-shaped layer connected with a cylindrical base through metallic cylindrical tube. The modeled design has the structure and the dimensions of a standard metallic cuff button. The proposed wearable antenna is designed to cover the dual ISM bands for both WLAN/Bluetooth (at 2.45 GHz) and Hiper LAN (at 5.8 GHz) applications with omni-directional radiation patterns. Very good agreement between simulations and measurements in terms of radiation performance is observed.

Acrylic substrate based low profile wearable button antenna with FSS layer for WLAN and Wi‐Fi applications

ABSTRACTIn this letter, a low profile circularly polarized wearable antenna with the appearance of a button on clothing for Wi‐Fi and WLAN applications is presented. The radiating elements of the antenna are made of copper sheet while a transparent acrylic fiber sheet material is used as substrate and fed by a coaxial line through the ground plane. The proposed antenna is simulated by Ansoft high frequency structure synthesis finite element method‐based (HFSS FEM)‐based EM simulator and has been optimized to operate within the Wi‐Fi and WLAN frequency bands (5250–5850 MHz) with center frequency of 5.25 GHz. A split ring‐shaped slot‐based frequency selective surface (FSS) is designed to enhance the gain of the proposed antenna. The peak gain of the antenna is found to increase from the conventional antenna gain of 2.1 to 5.1 dBi with the superstrate along with a bandwidth enhancement of 290 MHz. The composite FSS antenna is fabricated and the maximum measured gain of 5.1 dBi matches well with theoretical value. The antenna gets miniaturized around 34% by the slits with its circular polarization characteristic well maintained. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:1033–1038, 2015

A miniaturized wearable button antenna for Wi‐Fi and Wi‐Max application using transparent acrylic sheet as substrate

ABSTRACTA compact miniaturized wearable antenna with the appearance of a button on clothing for Wi‐Fi and Wi‐Max applications as well as used for body centric communication is presented. The radiating elements of the antenna are made of copper tape, while the substrate is given a property of transparent acrylic fiber sheet material and fed by a coaxial line through the ground plane. The proposed antenna is simulated by Ansoft HFSS finite element method based simulation software and has been optimized to operate within the Wi‐Fi and Wi‐Max frequency bands with center frequency of 5.5 GHz (5250–5850 MHz). The measured peak gain of this antenna is 2.92 dBi. There is a good matching between the simulated and the measured result. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:45–49, 2015

Button antenna on textiles for wireless local area network on body applications

A design of a wearable antenna for wireless local area network (WLAN) applications is presented in this study. The antenna consists of a button shape outer cylindrical structure and an internal central via connected to a top disc at one end and the metal ground plane at the other. The overall size and shape achieved are those of a standard metal jeans button which camouflages the antenna for wearable applications. The rigidness of the structure is greater than for previous wearable button antenna developments. The proposed wearable antenna is designed for 2.4 and 5 GHz with monopole-type radiation patterns at each band. This allows for transmission to other worn devices on the body. An investigation into the measured permittivity of cotton denim is presented and a section on the equivalent circuit modelling of the antenna and the fabric is given.

Covert dual-band wearable button antenna

A novel dual-band antenna for wearable WLAN computing applications is introduced. This antenna comprises three discs and a coaxial post. Its appearance is of a standard metal button of the type used in denim jeans. The antenna is easily disguised and less sensitive to clothing than printed patches, which use the textile fabric as a substrate or superstrate. The antenna requires no external matching circuitry and operates at 2400 and 5200 MHz. The radiation patterns are omnidirectional around the central post of the antenna.