A Triple-Band and High-Gain Circularly Polarized Rectenna for Radio Frequency Energy Harvesting Applications

This paper demonstrates a triple-band circularly polarized (CP) rectenna for radio-frequency energy harvesting (RFEH) applications in the 5G (3.5 and 4.9 GHz) and WLAN/Wi-Fi (5.8 GHz) bands. Initially, we introduce a detailed overview of the triple-band impedance matching network and its integration into the rectifier circuit. The working principles of the impedance matching network are comprehensively analyzed, followed by the design, manufacture, and experimental validation of a triple-band rectifier functioning at 3.5/4.9/5.8 GHz. Under −10 dBm input power condition, the measured power conversion efficiencies (PCE) are 36.8%, 26.9%, and 22.6% at the respective operating frequencies. Then, a high-performance broadband CP slot-coupled magnetoelectric (ME) dipole antenna is developed to facilitate the receiver functionality for the proposed rectifier. The ME-dipole antenna incorporates novel design technologies to enhance CP radiation performance, providing high gain and a wide impedance/axial ratio (AR) overlap bandwidth (3.18–6.27 GHz). It is well-suited for RFEH systems covering the 3.5/4.9/5.8 GHz bands. Ultimately, the antenna is integrated with the rectifier via a coaxial adapter to obtain a completed rectenna system, and its performance is rigorously evaluated. Experimental results confirm that the proposed rectenna exhibits a competitive PCE, establishing it as an ideal choice for RFEH applications.