Study on Wireless Power Transfer between Array Antennas in the Radiative Near Field towards Higher Efficiency

摘要

In this paper, we analyzed the wireless power transfer between array antennas in the radiative near field. We can calculate the power transmission efficiency between array antennas by regarding array them as aperture antennas. However, it is re-portedthat there is a considerable gap between theoretical efficiency and measured one in the previous study. As the reason, the theoretical calculation doesn't consider losses which occurs in the transmission. In the previous study, losses were estimated butthe examination of concrete loss factors is insufficient. In the radiative near field, an incident wave on receiving antenna is a spherical wave and a loss occurs in power combined circuit because the amplitude and phase of spherical electric field aredifferent at each element. We call it synthesis loss and this was not considered in the previous study.