RF energy harvesters for wireless sensors, state of the art, future prospects and challenges: a review

Abstract

The power consumption of portable gadgets, implantable medical devices (IMDs) and wireless sensor nodes (WSNs) has reduced significantly with the ongoing progression in low-power electronics and the swift advancement in nano and microfabrication. Energy harvesting techniques that extract and convert ambient energy into electrical power have been favored to operate such low-power devices as an alternative to batteries. Due to the expanded availability of radio frequency (RF) energy residue in the surroundings, radio frequency energy harvesters (RFEHs) for low-power devices have garnered notable attention in recent times. This work establishes a review study of RFEHs developed for the utilization of low-power devices. From the modest single band to the complex multiband circuitry, the work reviews state of the art of required circuitry for RFEH that contains a receiving antenna, impedance matching circuit, and an AC-DC rectifier. Furthermore, the advantages and disadvantages associated with various circuit architectures are comprehensively discussed. Moreover, the reported receiving antenna, impedance matching circuit, and an AC-DC rectifier are also compared to draw conclusions towards their implementations in RFEHs for sensors and biomedical devices applications.

Development of 2400–2450 MHz Frequency Band RF Energy Harvesting System for Low-Power Device Operation

“…The rectifier holds significant importance in determining the overall efficiency of an RFEH system, given that the RF signals captured are initially in the form of narrowband AC voltage signals characterized by lower power density [20]. It is essential to rectify these signals to convert them into useful DC voltage signals [21]. The development of efficient rectifiers and voltage boosters has been a prominent focus of research over the years.…”