A High Performance All-Textile Wearable Antenna for Wristband Application

Area of Science:

• Electrical Engineering
• Electromagnetics
• Wearable Technology

Background:

• Wearable devices require compact and efficient antennas operating in specific frequency bands.
• Existing antenna designs may face challenges with form factor, bandwidth, and human body proximity effects.

Purpose of the Study:

• To propose and validate a compact, conformal, all-textile wearable antenna for the 2.45 GHz ISM band.
• To optimize the antenna design for a small footprint suitable for wristband applications.
• To evaluate the antenna's performance under free space and human body loading conditions.

Main Methods:

• Design and fabrication of a monopole antenna integrated with a 2x1 Electromagnetic Band Gap (EBG) array.
• Optimization of EBG unit cell for the target frequency band and bandwidth maximization using a floating EBG ground.
• Performance analysis including free space testing, human body loading effects, and Specific Absorption Rate (SAR) calculation.

Main Results:

• The proposed antenna achieves a bandwidth of 2.39 GHz to 2.54 GHz.
• The antenna exhibits a compact footprint of 35.4 x 82.4 mm².
• The design maintains performance near the human body, with a SAR value of 0.297 W/kg at 0.5 W input power, indicating safety.

Conclusions:

• The developed all-textile wearable antenna is suitable for wristband applications in the 2.45 GHz ISM band.
• The integration of an EBG array enables a compact form factor and robust performance.
• The antenna design is confirmed to be safe for use in wearable devices due to low SAR values.