Experimental Study on Multi-Hop Wireless Power Transfer

This research is devoted to an experimental study on radiofrequency (RF) wireless power transfer (WPT) employing multi-hop technology. A special multi-hop node (MHN) that uses GHz radio waves has been developed for the study. The multi-hop node design is based on Yagi-Uda antennas, a voltage doubler-based RF-DC converter, a two-stage amplifier and a capacitor for energy storage. The experimental study is performed in laboratory conditions emulating a real-life environment with line-of-sight propagation with 27 dBm transmitted power and a 3.8-6.5 m distance range. The experimental setup comprises a transmitter, a multi-hop node, an edge node equipped with a voltage-doubler-based RF-DC converter, as well as measurement equipment. The wireless power transfer efficiency measurements for direct (without the multi-hop node) power transfer scenarios are also performed to evaluate the efficiency of the multi-hop-based WPT. The edge node received averaged power in both cases and RF-DC converted voltage is measured and analyzed.