Focused Radiative Wireless Power Transfer Experiments

In this paper we will report on first experiments carried out with pulse-delayed transmission to create focal areas or `bubbles' of high RF energy density. Through a proper transmission of delayed pulses by an array of antennas it will be possible to realize a peak power gain relative to a non-pulsed transmit (array) antenna. This gain can equal the number of array elements squared, as will be verified experimentally. Experiments are performed with an array consisting of two radiating elements. The use of the high RF energy density `bubbles' will be demonstrated by switching the focal point between two rectennas positioned in front of the transmitting array.