A sustainable screen-printed Class-C rectifier for energy harvesting and wireless power transfer

This paper presents a novel, sustainable microwave Class-C rectifier for radio frequency (RF) energy harvesting and wireless power transmission. The proposed rectifier is fabricated using screen-printing techniques, utilizing a conductive layer made of silver nanoparticle ink and a sustainable cork substrate. The proposed rectifier consists of a simple matching network, a shunt diode, a Class-C harmonic termination structure and a resistive load. The proposed rectifier is designed to operate at f = 2.4 GHz, achieving a peak power conversion efficiency (PCE) of 64% at an RF input power (PIN) level of 24 dBm and an optimal load (RL) of 160 Ω. In the latter case, a DC-DC boost converter and a supercapacitor (C_OUT = 0.33 F) are employed to ensure adequate DC voltage for powering Internet of Things (IoT) devices, validating the rectifier's performance. The proposed system successfully demonstrates the charging of both the DC-DC booster and the supercapacitor across different P_IN levels. Notably, this is the first time that a Cork substrate has been utilized for designing a microwave Class-C rectifier circuit, highlighting its potential for future sustainable IoT applications and RF circuitry design.