High-Efficiency and Compact RF Rectifier Design for Wireless Sensors in Extreme Environments

Abstract

Radio frequency (RF) energy harvesting garners significant attention for prolonging the lifespan of wireless sensor networks (WSNs). However, its deployment in extreme environments is constrained by low RF power. Therefore, to guarantee the sustained functionality of WSNs, it is imperative to enhance rectification efficiency at low incident power. This letter proposes a novel rectifier with highly efficient operation at low incident power. The rectifier comprises a T-type power divider with a ${CLC}$ $\pi$ network and two identical subrectifiers. Utilizing this, the reflected power from the subrectifiers can be reinjected into the rectifier so that it can be reused, and the rectification efficiency can be improved. Theoretical analysis and performance comparison are carried out. The experimental results indicate that the proposed rectifier is capable of achieving high rectification efficiency at low incident power. The recorded efficiency remains notably above 10% at an incident power of −$ 30\text{ dBm}$, with an operating bandwidth of up to $ 320\text{ MHz}$.