A DC Combining-Free Miniaturized Mirror-Like Rectenna System With Full-Wave Rectification for Robust Wireless Power Transfer in IoT at 2.45 GHz

Abstract

This letter presents a planar, fully integrated multisector mirror-like rectenna array designed for efficient microwave power transfer to charge the Internet of Things (IoT) sensor nodes wirelessly. The proposed system addresses limited power harvesting and dc combining challenges by directly integrating four radially arranged endfire rectifying antenna (EFRA) elements surrounding a centrally located bore-sight rectifying antenna (BSRA) element on both sides of the proposed system like a mirror without using dc combining networks. The proposed design facilitates direct conjugate matching of the system to reduce the insertion losses, enabling a compact and fully integrated design. This provides nearly 3-D coverage and makes it a good candidate for IoT applications. The mirror-like rectenna system (MLRS) system can harvest approximately 1400 mV of open dc voltage in any orientation and direction, sufficient to recharge and operate low-power IoT sensor nodes. The experimental setup further validated these results, demonstrating the system’s potential as a robust solution for wireless power transfer (WPT) in smart applications.