Diversity Measurements for On-Body Channels Using a Tri-Polarization Antenna at 2.45 GHz

Characteristics and diversity performance for on-body communication systems using a tri-polarization antenna are investigated based on measurements at 2.45 GHz. A disk-loaded monopole has been used as a transmitter, and a low-profile planar tri-polarization antenna as a three-branch receiver. Measurements were conducted for six typical on-body scenarios, where standing and sitting postures are considered. Envelope correlation and cross-polar discrimination (XPD) are calculated from measurement data. The tri-polarization diversity performance is evaluated by diversity gain, when different signal combing techniques are employed. Diversity gain is high for the non-line-of-sight scenarios and increases with increasing mobility. Tri-polarization diversity outperforms dual-polarization diversity in terms of up to 16.33 dB higher path gain due to the full utilization of polarization resource of electromagnetic wave and the avoidance of polarization mismatch for the dynamic on-body channels.