Far-field wireless power delivery and power management for low-power sensors

This paper presents an overview of a system for wireless far-field powering of unattended distributed wireless sensors, including the power reception device design and optimization, power transmission, power management and control. Design and measured data of implementations of the various parts of the system in the 2GHz cellular and 2.45GHz unlicensed bands will be shown. A design methodology for antennas integrated with rectifiers (rectennas) optimized for efficiency at low incident power levels (5-100uW/cm²) will be presented. Integration of rectenna elements and arrays with the electronic application (wireless sensing in this case) requires power management, and some approaches that consume very low power levels will be presented. Possible applications such as sensors for comfort, performance and security of commercial and residential buildings will be discussed.