Discharge characteristics as the criteria for replacing batteries with power harvesting circuits in sensor systems

This paper describes the design and development of a cellular near-field power harvesting circuit. Its potential to independently power sensor systems without batteries is demonstrated and discussed. As universal criteria to decide which batteries in sensor systems can be directly replaced by the proposed power harvesting circuit, discharge characteristics of Lithium and Alkaline batteries were investigated and compared to the measured discharge characteristic of the proposed power harvesting circuit. Results show that it is easy to replace Alkaline batteries directly whereas if Lithium batteries are to be replaced by the proposed power supply, an efficient voltage regulating circuit must be used.