RF-dc Converter Optimization using MIMO Antennas and OTA Multi-Sine Calibration Method

In this paper, the optimization of the power transmitted from several non-collocated antennas to an RF-dc converter circuit is performed using an Over-The-Air (OTA) multi-sine feedback method. An experimental system is tested in an indoor environment and the OTA multi-sine calibration method is applied to produce constructive interference at the RF-dc converter location. It is shown that its overall performance is improved for different indoor positions. Experimental results demonstrate the effectiveness of using the proposed method for Wireless Power Transfer (WPT) applications since the RF-dc converter presents higher efficiency when the method is applied even in worst scenarios, such as low input power or larger distance.