RF Energy Harvesting for Embedded Systems: A Survey of Tradeoffs and Methodology

This paper presents an overview of passive Radio Frequency (RF) energy reception and power harvesting circuits for isolated communications and computing systems lacking access to primary power sources. A unified understanding of the energy harvesting alternatives is provided, followed by an elaborate study of RF energy harvesting within the context of embedded systems. A detailed discussion of RF technologies ranging from the directed communications signal reception to dispersed ambient power harvesting is provided. A comparative focus on design tradeoffs and process alterations is provided to represent the diversity in the applications requiring wireless RF harvesting units. Also included is an analysis of system combinations, and how wake up units, active storage, and duty cycling play roles in the consumption and harvesting of RF energy.