A Parasitic Strip Loaded Broadband Circularly Polarized Antenna for 5 GHz WBAN Full- Duplexing

Wearable antennas operating in the 5 GHz (5.15 – 5.825 GHz) have gained increasing attention due to their promising potential, offering approximately 1 GHz of bandwidth and data rates up to 10 Gb/s. This study introduces a parasitic strip-loaded, low profile, dual circularly polarized (DCP) antenna for 5 GHz WBAN (wireless body area network) applications. A semi-flexible Rogger 5880 substrate is used to design the proposed structure. Performance improvements in impedance bandwidth (IBW), port isolation and axial ratio (AR) bandwidth are achieved through the integration of two parasitic strips positioned or-thogonally to the feed lines. The antenna demonstrates co/cross-polarization isolation of over 18 dB, making it highly suitable for full-duplex WBAN applications. For robustness evaluation, simulations on a human body model are conducted, revealing a maximum specific absorption rate (SAR) of 1.22 w/kg, ensuring compliance with safety standards. The measured peak gain of 3.4 dBi is observed in the free space with port isolation > 26 dB in the band of interest (5.15 – 5.825 GHz). These attributes make the proposed antenna an optimal solution for 5 GHz WBAN full-duplexing.