A Flexible Planar Antenna on Multilayer Rubber Composite for Wearable Devices

Abstract

Abstract-This paper presents the design of a flexible antenna using planar dipole with a reflector to achieve optimal radiation efficiency and low specific absorption rate (SAR) when the antenna is placed directly over the skin of body model. The antenna is designed for the 2.45 GHz frequency band. The parametric analysis of the proposed antenna is carried out. The proposed antenna achieves stable onbody performance: |S 11 | varies from −16.05 dB (on skin) at 2.47 GHz resonant frequency to −16.40 dB (in free space) at 2.44 GHz resonant frequency. It was found that the maximum 1 g average SAR value is only 0.23 W/kg for an input power of 100 mW when the antenna is placed directly over the skin of a three-layer body model, and radiation efficiency is 20.5%. The measured results are presented to demonstrate the validity of the proposed antenna.

Natural rubber–based composites filled with bioglasses from a CaO‐SiO2‐P2O5‐Ag2O system. Effect of Ag2O concentration in the filler on composite properties

“…These antennas are light, can take the desired shape of the object, and can follow movements and change its shape . In all cases, the substrate and the insulating layers between the elements of these flexible antennas are filled elastomeric composites . However, the requirements for these composites are too serious: They must not change their characteristics under bending or pressure; they must have low relative permittivity to reduce signal propagation delay, low loss tangent to reduce signal attenuation along with better signal performance, mechanical flexibility, high dimensional stability, moisture absorption resistance, and high thermal conductivity to dissipate the heat generated .…”

Fully Textile Dual-Band Logo Antenna for IoT Wearable Devices

“…As a result, IoT devices are heterogeneous in appearance and functionality [10]. However, each wearable device generally includes one or more sensors, a processor, an operating system, a transceiver, and an antenna [11,12]. Such devices can be embedded in clothing or accessories, transmitting and receiving data wirelessly [11,13,14].…”

“…However, each wearable device generally includes one or more sensors, a processor, an operating system, a transceiver, and an antenna [11,12]. Such devices can be embedded in clothing or accessories, transmitting and receiving data wirelessly [11,13,14]. To be easily integrated into clothing and accessories, such as bags, backpacks, or pockets, wearable antennas must be flexible and light, which is why textile antennas are widely used in wearable devices [15][16][17][18].…”

Natural rubber composites containing low and high dielectric constant fillers and their application as substrates for compact flexible antennas

“…2 In all cases, the pad and the insulating layers between the elements of those flexible antennas are filled with elastomeric composites. 3 -6 However, the requirements for these composites are too serious: They should not change their flexural or pressure properties, they should have a low relative permittivity to reduce signal propagation delay, low loss tangent to reduce signal attenuation along with better signal performance, mechanical flexibility, high dimensional stability, moisture absorption resistance, and high thermal conductivity to dissipate the heat generated. 7 -10 Natural rubber (NR) has the potential to be used in such applications as it has a relatively low cost, is easy to process, has high elasticity and water resistance, has stable electrical properties, and what is particularly important—it is a product that comes from renewable sources and is environment-friendly.…”