Dual-Band Store-and-Use System for RF Energy Harvesting With Off-the-Shelf DC/DC Converters

RF energy harvesting (RFEH) has recently become part of the alternatives for powering wireless sensor networks. Our focus in this article was to introduce a design, MSwitch, able to use off-the-shelf dc/dc converters for running a real and self-powered Internet of Things (IoT) application. MSwitch is an RF dual-band energy harvesting stage employing the store-and-use principle that mixes efficiently and in a dynamic manner both inputs. We proved an increase on the performance with respect to the single-band case and to the most successful approaches found in the literature, achieving about 10 % better efficiency and around 35 % lower minimum power levels. Besides, we carried out an analysis of the commercial dc/dc converters, characterizing them for ultralow-power conditions. Likewise, we analyzed the state-of-the-art rectification circuits and commercial Schottky diodes, searching the best performance under our RFEH conditions. Finally, we manufactured our designs as a complete system and demonstrated its operation with an IoT concrete application.