A Compact Button Antenna with Dual-Band and Dual-Polarization for Wearable Body Area Networks

Area of Science:

• Electrical Engineering
• Electromagnetics
• Biomedical Engineering

Background:

• Wireless Body Area Networks (WBANs) require efficient antennas for reliable communication.
• Existing antennas often struggle with dual-band operation and polarization diversity needed for varied communication scenarios.
• The Industrial, Scientific, and Medical (ISM) bands (2.45 GHz and 5.8 GHz) are crucial for WBAN applications.

Purpose of the Study:

• To design and validate a compact, dual-band, dual-polarization button antenna for WBANs.
• To achieve distinct radiation patterns and polarizations for on-body and off-body communication.
• To ensure the antenna meets safety regulations for wearable devices.

Main Methods:

• Antenna design utilizing a top-loaded monopole for the lower band and a cross-dipole for the higher band.
• Fabrication of a prototype antenna.
• Performance characterization through free-space and on-body measurements.
• Specific Absorption Rate (SAR) simulations on a human model.

Main Results:

• The antenna operates effectively in the 2.45 GHz and 5.8 GHz ISM bands.
• Achieved 18.3% fractional bandwidth with linear polarization (omnidirectional) for on-body communication.
• Achieved 66.4% fractional bandwidth with circular polarization (broadside) for off-body communication.
• Prototype measurements validated dual-band and dual-polarization performance.
• SAR simulations confirmed compliance with safety limits.

Conclusions:

• The developed button antenna is suitable for WBAN applications due to its compact size, dual-band/dual-polarization capabilities, and safety compliance.
• The antenna's design enables versatile communication strategies for wearable systems.
• This work contributes to the advancement of reliable and safe wireless communication for healthcare and personal monitoring.