Impact of the Antenna-Body Distance on the WBAN Channel Characteristics
This paper presents a simulation based study on the impact of the antenna-body distance on the ultra wideband (uwb) on-body radio channel characteristics. The antenna used in this study is a recently published highly directional cavity-backed uwb antenna, designed for inbody communications, e.g. capsule endoscope localization. The on-body channel characteristics are evaluated both in frequency and time domains with several antenna-body distances as well as with several antenna location options. Furthermore, the impact of the antenna-body distance is evaluated by studying 3D power patterns, which also provide information about the propagation depth within tissues in different antenna-body distances. It is shown that antenna-body distance has a significant impact on the on-body channel characteristics. In time domain the difference can be 15 dB between the main peaks of the impulse responses whereas in frequency domain, the path loss difference can be even 30 dB within the frequency band of interest. Besides, antenna-body distance has a clear impact on the propagation depth inside the tissues as well.