Compact UWB antennas for Wireless Body Area Networks (W-BANs)

A major issue in Wireless Body Area Networks (W-BAN) is the reliability of the transmission in all conditions, thus in all locations and positions of the wearer. One way to achieve this is to design communication systems as independent as possible to the presence of the wearer, and to use multiple antennas (diversity, MIMO) to overcome fading. Polarization diversity is a good candidate for W-BAN, as it allows for the design of compact antennas having potentially a good diversity gain. Ultra Wide Band (UWB) has proved to be good candidate for W-BAN, in the case where high data rates over short ranges are targeted. In order to achieve polarization diversity, both UWB antennas having a polarization orthogonal and parallel to the surface of the wearer are required. While the latter are easy to design, it is not obvious design low profile UWB antennas with a vertical polarization. Moreover and for both cases, the design of antenna elements coupling as little as possible to each other or to the wearer is a key issue to the final quality of the system. In this contribution, we present a low profile UWB antenna having a polarization orthogonal to the wearer, which inherently minimizes the coupling to the body.