Indoor off-body channel measurements using miniaturized chip antennas with pattern diversity

In this paper, off-body channel measurements are proposed using miniaturized chip antennas (dimension: 7 × 2 × 1.20 mm³) under pattern diversity configuration at 2.2-2.3 GHz. The measurements were carried out in a multipath indoor laboratory environment using two sensors as transmitter and receiver deployed on-body and free-space, respectively where each sensor comprises two miniature chip antennas offering pattern diversity. The resulting radio channels have been recorded while varying the inter-sensor distance. Radio channel parameters such as link budget, power delay profile and capacity were extracted from the measured data. Results show that pattern diversity can offer improvement in perspective of link budget and channel capacity compared to single-input single-output system for off-body channels proving the suitability of miniaturized chip antennas for smart, low power body area networks.