Passive and Active Rectifier Combination for Hybrid Piezoelectric and Radio Frequency Energy Harvesting System

Energy harvesting (EH) systems are evolving and becoming practical in portability. These systems can be a good alternative to batteries for powering the wireless sensor networks (WSNs) as batteries have a limited lifespan. The main focus of this paper is the design and implementation of a two-stage rectifier circuit for a hybrid EH system. This system converts piezoelectric energy from walking, vehicle tries and road surfaces, as well as the radio frequency (RF) energy from the environment into the electrical energy. The first part of the circuit is a passive rectifier with MOSFET transistors for the piezoelectric EH system, which in addition to supplying power to the load, supplies electrical energy to the second part, which is an active rectifier for RF EH. The proposed Hybrid EH approach completely eliminates battery (as an external power) in portable electronic systems. It also ensures a continuous supply of electrical energy in all conditions in an autonomous EH system. In addition, by simultaneously receiving from several environmental sources, it enables the ability to transfer more power to the load. The combination of two types of active and passive rectifiers to be used for EH applications, as well as the use of a technique to avoid the overlapping area during the rectification, makes the proposed EH system as a reliable and usable one.