A New Backscattering Dual-Polarized Rectenna for Wireless Power Transfer and IoT Applications

This paper proposes an innovative dual-polarized backscattering rectenna that operates in two distinct modes — energy harvesting and backscattering modulation — driven by two-bit digital control signals. By utilizing two orthogonal (co- and cross-) polarizations, the design represents a versatile candidate for IoT applications such as battery-free wireless sensing, identification, localization, and communication. The rectenna’s dual functionality is validated through its integration into a proof-of-concept battery-free wireless sensor, where it operates both as an energy harvester and as a dual-polarized backscattering modulator. As a proof of concept, a 16-byte AES-128 encrypted payload is backscattered over the wireless power transfer link to enhance the resilience of a battery-free Bluetooth Low Energy (BLE) wireless sensor against replay, relay, and eavesdropping attacks.