Far-field low-power wireless powering for unattended sensors

This paper presents an overview of the design of components 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 is shown. A design methodology for antennas integrated with rectifiers (rectennas) optimized for efficiency at low incident power levels (1-100uW/cm²) is presented. Integration of rectenna elements and arrays with the electronic application (wireless sensing in this case) requires power management, and some approaches with low power consumption are presented.