Influence of antenna alignment and line-of-sight obstruction on the accuracy of range estimates between a pair of miniature UWB antennas

This paper presents an experimental analysis of the effect of physical orientation of a compact UWB antenna on the accuracy of range estimates between two such antennas using signal time-of-flight. A pair of identical miniature UWB antennas have been used for the investigations, in which one of the antennas is rotated in various directions in the vertical plane and the effect of this rotation on the range estimates has been studied. The analysis has also been carried out with the antennas mounted on a human arm. Moreover, the impact of non-line-of-sight communication on the range estimation between the antenna pair has also been examined by using different types of materials as obstruction to line-of-sight between the two antennas. Channel Impulse Response and peak detection techniques have been employed for range estimation. It has been demonstrated that range estimates can be done with sub-centimetre accuracy even when the antenna is tilted in various directions in the vertical plane. High level of ranging accuracy is achieved even in the non-line-of-sight scenario and when the antennas are mounted on the human body.