Design of an Improved Low‐Profile, Electrically Small Rectenna for Wireless Energy Transmission

Abstract In light of the characteristics of traditional wireless power transmission (WPT) systems, which include large size, low efficiency, and complex processing, this paper proposes a novel electrically small, low‐profile, and high‐efficiency Huygens source rectenna that can be effectively applied to 915 MHz wireless power transmission systems. The receiving antenna utilizes near‐field resonant parasitic elements and incorporates a design featuring a folded electric dipole and an “”‐shaped magnetic dipole to achieve antenna miniaturization, with an electrical size ka of 0.724, making it easy to fabricate and cost‐effective. By closely integrating it with a rectifier designed for low load, it exhibits a significant capability for capturing electromagnetic waves. Simulation results indicate that the circuit achieves a maximum rectification efficiency of 70%. The experimental results and simulation show good consistency. At an input power of 19.5 dBm, it achieves over 60% RF‐to‐DC conversion efficiency, making it more suitable for applications in wireless Internet of Things systems.