Towards high on-body sensor node performance with the 3D antennas for IR-UWB WBANs

The present paper examines on-body performance in the range of wireless body area network (WBAN) antennas by investigating a channel path gain, the applicability for launching creeping waves and a radiation pattern shape in the proximity of human tissues. The focus of the study is to compare the performance of the designed 3D antennas with an example of a planar antenna, of which the majority of the wearable radiators are comprised in the open literature. The designed antennas are optimized for the impulse radio ultra wideband (IR-UWB) WBANs and targeted for on-body sensor node purposes. The radiator structures have low profiles in the fundamental modes as λ/7 (discone), λ/10 (monopole with a bent ground) and λ/5 (monopole with a cylindrical ground). The antennas cover the Federal Communications Commission (FCC) UWB regulations. It was demonstrated that the 3D antennas can efficiently launch body´s surface wave propagation along a body surface in the longitudinal direction and around a body. The improvement of several tens of decibels over a planar antenna is able to obtain by the proper on-body design with a dominant normal polarization.