The Performance of On-Body Wearable Antennas in a Repeatable Multipath Environment

The performance of antennas designed for on-body channels is usually evaluated in an anechoic environment. However, it is also appropriate to determine their performance under multipath conditions since the presence of off-body paths may significantly improve on-body links for some antennas. This was investigated by considering the on-body performance (|S-21| path gain) of a range of wearable antennas in the repeatable multipath environment of a reverberation chamber using a tissue-equivalent experimental phantom, representative of human muscle tissue at 2.45 GHz. These results were compared with the equivalent measurements taken in an anechoic far-field chamber. The study shows that antennas which radiate tangential to the body surface, supporting a surface wave propagating mode, perform favorably in both environments, which is advantageous in reliable system design.