An international research team including scientists from the Moscow Institute of Physics and Technology and ITMO University has proposed a way to increase the efficiency of wireless power transfer over long distances and tested it with numerical simulations and experiments. To achieve this, they beamed power between two antennas, one of which was excited with a back-propagating signal of specific amplitude and phase. The study is detailed in a paper published in Physical Review Letters and briefly reported in the American Physical Society journal Physics.