A Plug-in Type Integrated Rectenna Cell for Scalable RF Battery Using Wireless Energy Harvesting System

Microwave power transfer is employed for charging self-sustainable internet of things (IoT) devices by wireless energy harvesting (WEH) using rectenna (Rx) and dedicated RF shower (Tx). The challenges for this implementation are the diverse power requirements of different devices and polarization and orientation mismatch between Tx and Rx. Different demands need redesigning rectennas, which can be avoided by scalable designs. A novel integrated rectenna devised as a plug-in-type unit cell is proposed for scalable RF battery. The plug-in feature allows multishape assemblies for the WEH system using multiple rectenna cells. This enables multiobjective-like dynamic power harvesting and orientation-insensitive operation. The rectenna cell designed with integrated matching has a high-gain endfire radiation pattern, which avoids blocking of incident waves and mutual coupling between adjacent rectennas. To illustrate scalability, linear-stacking and cuboid-shaped assemblies are evaluated for WEH performance. The results prove that the proposed scaling scheme with rectenna cells easily adapts to the user requirements.