A Flexible Circularly Polarized Crossed-Dipole Antenna with an EBG Reflector

A flexible circularly polarized (CP) crossed-dipole wearable antenna for 5.8 GHz wireless body area networks is proposed. The antenna employs flexible polydimethylsiloxane (PDMS) as the substrate, enabling seamless integration with the human body. Meander-line structures and an electromagnetic bandgap (EBG) are utilized to achieve miniaturization and high realized gain. Furthermore, circular polarization is achieved by connecting two pairs of mutually orthogonal meander-line dipoles using vacant-quarter rings. Additionally, each dipole arm incorporates two adjacent meander-line branches of different lengths to broaden the bandwidth. The antenna dimensions are 62.5 × 62.5× 5mm³. Simulated results show that, in the flat state, the proposed antenna achieves -10 dB impedance bandwidths of 18.5%, a 3-dB axial ratio (AR) bandwidth of 17%, and a peak realized gain of 12.7 dBic. Moreover, the simulated specific absorption rate (SAR) complies with both US and EU standards, confirming suitability for wearable applications.