Design of a UWB stacked antenna for body area network applications

UWB technology is a promising candidate for Body Area Network (BAN) applications, especially in radar and localization due to superior ranging capabilities in comparison to narrowband systems like RFID, and Wi-Fi. Centimeter precision is expected when using IR-UWB (Impulse Radio UWB) in ranging and localization, and given that the antennas have a crucial role in forming the radiated pulse, special attention has to be given to their design. Good IR-UWB BAN antenna should present following characteristics both in free-space and when placed in close body proximity: stable impedance and radiation pattern in the band, flat transfer function amplitude versus frequency, high value of impulse fidelity, and high radiation efficiency. In terms of physical characteristics the antenna should be small and low profile in order to be easily blended with user´s clothing or taped to the skin. To the best of authors´ knowledge there is no UWB antenna in the literature that satisfies all of mentioned conditions simultaneously. Therefore we will present here a stacked, two-layer UWB antenna that demonstrates high resistance to body proximity and satisfies all before mentioned characteristics.