Impact of feeding position on the performance and characteristics of small wearable on-ground antennas

In this paper, three commonly used on-ground antenna types (loop, monopole and planar inverted-F antenna) are compared in the scope of wireless body area networks (WBAN) for on-body communications at 2.45GHz. The bandwidth of the antennas can be enhanced by placing them towards the edge or the corner of the small ground plane (25×35mm2) which has, as a consequence, detrimental effects on radiation characteristics that motivates the examination of the impact of feeding location for on-body propagation in detail. The present study quantifies the trade-off between on-body efficiency, the gain in the direction tangential to the surface, applicability to launch creeping waves and bandwidth potential of the different antenna types with various feeding locations. The simulated channel gain |S21| around tissue-equivalent numerical phantoms is compared to an analytical WBAN path loss model.