Wearable, small, and robust: the circular quarter-mode textile antenna

A miniaturized wearable antenna, entirely implemented in textile materials, is proposed that relies on a quarter-mode substrate integrated waveguide topology. The design combines compact dimensions with high body-antenna isolation, making it excellently suited for off-body communication in wearable electronics/smart textile applications. The fabricated antenna achieves stable on-body performance. A measured on-body impedance matching bandwidth of 5.1% is obtained, versus 4.8% in free space. The antenna gain equals 3.8 dBi in the on-body and 4.2 dBi for the free-space scenario. High radiation efficiency, measured to be 81% in free space, is combined with a low calculated specific absorption rate of 0.45 mW/g, averaged over 1 g of tissue, with 500 mW input power

A review of wearable antenna research

With the rapid popularization of IOT applications, wearable devices have been widely used in many fields such as sports and health, entertainment and medical assistance. In addition to the early wearable form, more attachment and implantable wearable devices are constantly developed, and the development of these new wearable devices is largely due to the development of miniaturization antenna technology. This paper discusses the different realization methods and performance index requirements of wearable antenna, introduces the research situation of wearable antenna at home and abroad in recent years, and analyzes the development trend of wearable antenna

Robust, wearable, on-body antenna relying on half mode substrate integrated waveguide techniques

A compact, robust, wearable antenna for body-worn applications in the 2.4 GHz Industrial Medical and Scientific band is designed, fabricated and tested. This novel compact textile cavity backed slot antenna combines a half-mode substrate integrated waveguide topology with an additional row of shorting vias for miniaturization. Excellent free space performance is achieved with a measured 4.6 % impedance bandwidth, maximal gain of 4.7 dBi and radiation efficiency of 81.3 %. On-body measurements reveal minimal frequency detuning when the antenna is worn by a test subject as well as a negligible impedance bandwidth reduction to 4.5 %. The low calculated Specific Absorption Rate of 0.51 W/kg averaged over 1 g of tissue demonstrates high antenna body isolation. Therefore, this design is an attractive option as antenna in smart textile systems

Wearable antennas: design, connectivity and evaluation measurement techniques

Wearable antennas and electronics technology rapidly grows the last decades and leads to a future where smart textiles will be integrated into our garments. However the wearable technology research includes unsolved or of different approach challenges. This thesis deals with challenges regarding wearable antenna characterization and measurements, textile antennas feeding and textile transmission lines interconnecting. Regarding the wearable antenna characterization and measurements, a novel design of a liquid torso phantom and a new methodology for evaluating wearable antenna performance by using the cylindrical near field measurement technique are proposed. As for the textile antennas and transmission lines feeding and interconnecting, two novel methods are proposed

An active wearable dual-band antenna for GPS and Iridium satellite phone deployed in a rescue worker garment

An active wearable dual-band circularly polarized microstrip patch antenna for Global Positioning System and Iridium satellite phone applications is presented. It is constructed using flexible foam and fabric substrates, combined with copper-on-polyimide film conductors. A low-noise amplifier chip is integrated directly underneath the antenna patch. The antenna's performance is examined under bending and on-body conditions. The active antenna gain is higher than 25 dBi and the 3dB axial ratio bandwidth exceeds 183 MHz in free-space conditions. The antenna performance is robust to bending and on-body placement

Investigation of a Switchable Textile Communication System on the Human Body

In this paper, a switchable textile communication system working at 2.45 GHz ISM band is presented and studied for different locations within a realistic on-body environment. A 3D laser scanner is used to generate a numerical phantom of the measured subject to improve the accuracy of the simulations which are carried out for different body postures. For the off-body communications, the system is acting as an aperture coupled microstrip patch antenna with a boresight gain of 1.48 dBi. On-body communication is achieved by using a textile stripline, which gives approximately 5 dB transmission loss over 600 mm distance. The system is switched between on and off-body modes by PIN diodes. Common issues, such as shape distortion and body detuning effects which the textile antenna may experience in realistic use are fully discussed. Robust antenna performance is noted in the on-body tests, and an additional 3 dB transmission coefficient deduction was noticed in the most severe shape distortion case

Novel wearable antenna systems for high datarate mobile communication in healthcare

In critical healthcare applications, there is a need for reliable wideband mobile communication links, implemented by portable units with sufficient autonomy. We present the latest generation wearable antenna systems for invisible and comfortable integration in patients' or caregivers' garments. These active textile modules boast excellent performance and reliability, thanks to innovative antenna topologies, leveraged by the application of substrate integrated waveguide technology, pervasive integration of electronics and energy harvesters, and the application of multi-antenna processing techniques. Applications range from mobile communication links between caregivers and a coordination centre during interventions, over wireless sensor systems for patient monitoring, to relaying videos streams between a wireless endoscopy capsule and a remote control station

Environmental electromagnetic characterization framework for wearable antenna materials

In wearable antenna design, the prevailing atmospheric conditions can have a significant effect on the electromagnetic properties of the fabric substrate and hence the resulting antenna performances. Therefore, an accurate characterization of this effect is an important issue in textile antenna design. This paper presents a dedicated constitutive parameter extraction method as a function of relative humidity of all materials used. The method relies on a comparison between measured and simulated antenna figure's of merit in order to extract complex permittivity of the substrate and effective bulk conductivity of the e-textile. A two-step approach is used for separating conductor losses from substrate losses. The problem of finding the best fit between simulated and measured data is solved by relying on a surrogate based optimization technique. Here, two fabric materials are characterized for relative humidity levels ranging from 10% to 90%

Analysis Of Wearable Antenna Using Electromagnetic Band Gap Under Bending Conditions

Wearable antenna caught many attentions among researchers due to its wide applications in the technology.The wearable antenna can be widely applied in military, medical,tracking,and many other fields due to its capability to function on the body and off the body.It is an advantage if the wearable antenna could operate with wide bandwidth.However,there are some drawbacks when designing wideband antenna.Backward radiation is one of the major drawbacks introduced by a wearable antenna. Therefore,it is crucial to reduce the backward radiation to avoid harm to the user.Hence,this thesis presents a wearable antenna integrated with Electromagnetic Band Gap (EBG) structure to perform at particular dual-band Wireless Local Area Network (WLAN) frequencies;2.4 GHz and 5.2 GHz.EBG structure is a type of metamaterial which cannot be found in nature.This structure has become one of the interests due to its extraordinary response to electromagnetic waves.The wearable antenna is designed in the form of circular ring microstrip patch antenna.Jeans have been used as the medium of the substrate.Jeans fabric is selected due to its high permittivity and inelasticity compared to the other materials.The overall size of the antenna is 70x70mm.In order to improve the performance of the antenna,an EBG is then designed to be integrated with the proposed wearable antenna.Next,the designed structures have been fabricated and measured for return loss,gain,directivity,and radiation pattern.The integration of the wearable antenna with the EBG structure has improved the overall performance.The gain of 5.711 dB and 7.474 dB has been achieved for both high and low resonating frequencies respectively,which shows\ud almost 63.7% improvement at low frequency and 121.4% at high frequency.As the designed antenna is designed to be worn on the body,the bending effect of the structure is studied.Cylindrical foams are used to replace human torso for this purpose.Three radiuses have been selected, representing adult's wrist,arm,and thigh.The overall structure is then been tested under bending conditions; resulting intangible effect to the antenna's performances compared to the flat antenna.The return loss for the antenna was found to be very little affected by the presence of body which makes the designed antenna to be suitable for the wearable communication system.Thus,this antenna is suitable for WLAN application purposed especially for medical,consumer electronics sectors and military field.The details of the measured and simulated are presented and discussed