A dual broadband butterfly loop antenna for body wearable applications

Abstract

A dual broadband flexible butterfly loop antenna is designed to be worn on a human body which covers several important bands for wearable applications including the MedRadio band 402-406 MHz and ISM bands (433-434, 902-928 and 2400-2483.5) MHz. This antenna offers two wide bands for the reflection coefficient S11 -10 dB from 430-1003 MHz and 2004-2700 MHz with bandwidths of 573 and 696 MHz respectively. The MedRadio band is covered with S11 under -6 dB. This feature gives the antenna robustness against the frequency detuning effects of the body and makes it suitable for in-body services such as communication and wireless power transfer.