A Pattern and Polarization -Reconfigurable Fully-Textile Wearable Antenna

A single-layer textile pattern and polarization reconfigurable patch antenna that operates within the 2.4 GHz industrial, scientific, and medical (ISM) band is numerically investigated for wearable applications. Four pairs of metallic snap-on buttons are integrated into the main corner-truncated and stub-loaded radiated patch to serve as detachable shorting pins. By engaging/disengaging the buttons, the textile antenna can achieve a monopole-like radiation pattern with linear polarization or a patch-like radiation pattern with circular polarization enabling on- and off-body wireless communication, respectively. Simulations indicate that by applying two parasitic elements gap-coupled into the non-radiating edges of the main patch, both the impedance bandwidth and axial ratio bandwidth are enhanced in the off-body communication mode. A multilayer tissue phantom is used to emulate realistic wearing conditions. Resonance and radiation performance characteristics of the proposed antenna are examined in both radiation modes. The specific absorption rate (SAR) is, also, evaluated in terms of safety.