Enabling Multi-Spot Wireless Power Transmission via Pulsed FDA for Simultaneous Dislocated Charging

In this work the beam steering capability of pulsed frequency diverse arrays (pulsed FDAs) is analyzed and experimentally validated for the wireless energization of battery-less sensors randomly placed in a digitalized environment. The measurements, carried out for a 4-finger planar array operating at 1.9 GHz, show how it is possible to illuminate different regions of space “almost” simultaneously, by periodically selecting the a priori known raising time instants of the control pulses of the array excitations. The multi-sine generated signal is used as the input of a rectifying circuit, designed to face with the pulsed nature of the excitation. The simulated results demonstrate the feasibility of the envisaged powering system, where the outstanding reconfigurable capabilities of a pulsed FDA, as smart power source, guarantee RF-to-dc conversion efficiencies comparable to the standard continuous wave (CW) case.