Flexible EBG-backed PIFA based on conductive textile and PDMS for wearable applications

A wearable planar inverted-F antenna (PIFA) fed by the coplanar waveguide (CPW) and backed with an optimized electromagnetic bandgap (EBG) structure is presented. The antenna is made of conductive textile and polydimethylsiloxane (PDMS), which is a conformal and robust solution to wearable applications. The EBG unit cell is miniaturized according to the equivalent circuit model, and the cross-polarization is suppressed due to its approximate 180 degrees reflection phase in the orthogonal direction. The measured impedance bandwidth ranges from 2.30 to 2.65 GHz, which covers the 2.4 GHz Industrial Scientific Medical (ISM) band. The antenna keeps a high gain and efficiency above 70% under different conditions including being flat, bent, and close to the human body. The maximum SAR value is limited to 0.612 and 0.330 W/kg under 1 and 10 g standard, respectively. Therefore, the antenna is a promising candidate for wearable applications in various domains.