A compact multiband flexible antenna with a full ground plane for off body communication

A compact, multiband flexible antenna for off-body communication at 2.45 GHz and ultrawideband (UWB) low and high bands is presented as required by the IEEE 802.15.6 (TM) standard, 2012. The antenna exhibits a directional radiation pattern and provides good gain along with a low specific absorption rate (SAR). The proposed antenna has a compact footprint of 44 x 32 x 1.5 mm3. It is fabricated by placing conductive fabric on a 1.5 mm thick polydimethylsiloxane (PDMS) polymer to enhance flexibility and durability. A full ground made of conductive textile is used on the underside of the dielectric to reduce the load directed toward the antenna from the layers of human tissue beneath it and to minimize back radiation from the human body. The proposed antenna design combines square and circular rings to achieve multiband characteristics. Edge chamfering, slotting, and stub addition are employed as bandwidth expansion techniques to achieve wide bandwidth. The antenna demonstrates exceptional resistance to the human body's load and physical deformation. To the authors knowledge it is the compact single-layer substrate flexible FGP antenna operable in the WLAN (2.45 GHz), lower (3.2-4.6 GHz), and higher UWB (6.2-11 GHz) bands specified by IEEE 802.15.6.