Flexible circularly polarized antenna with axial ratio bandwidth enhancement for off?body communications

A flexible circularly polarized (CP) wearable antenna is proposed for a wireless body area network at the 5.8-GHz industrial, scientific, and medical band. The made of polyimide foam material. CP radiation enabled by loading two pairs shorting pins on rectangular patch antenna. 3-dB axial ratio (AR) bandwidth doubled adding inverted L-shaped parasitic stubs both sides For validation, with dimensions 0.68?0 × 0.044?0 was fabricated measured in various scenarios an impedance 6.6% (5.67–6.05 GHz), AR 3.85% (5.730–5.955 peak gain 7.2 dBi. off-body direction achieved half-power beamwidth 65° 84°. With specified input power 100 mW, specific absorption rates are 0.613 0.294 W/kg 1-g 10-g average tissues. Moreover, through analysing link budget reliable communication can be guaranteed within 20 m indoor line-of-sight environments.