Dual-Band Wearable Antenna for On Body Communication

This work presents a dual-band antenna design methodology using Characteristic Mode Analysis (CMA). The proposed antenna consists of two eccentric circular rings fed by a coplanar waveguide (CPW). The dual-band antenna has a small size of <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$0.29\lambda_{0}\times 0.24\lambda_{0}\times 0.006\lambda_{0}$</tex> (where <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\lambda_{0}$</tex> represents the wavelength at the lowest frequency in the free space). The observed impedance bandwidth (at <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$(S_{11}\leq-10\ \mathbf{dB})$</tex> is 89.4% from 2.18 GHz to 4.37 GHz and 9.2% from 4.93 GHz to 5.41 GHz. These bandwidths cover Bluetooth, Zigbee, LoRa, 4G/5G sub-6 GHz, and Wi-Fi 5G technologies corresponding with 2.45 GHz, 3.8 GHz and 5.2 GHz bands. The antenna performs well even when placed on the human body for on body communication applications.