Abstract
The paper describes the design and implementation of power management circuits for RF energy harvesters suitable for integration in wireless sensor nodes. In particular, we report the power management circuits used to provide the voltage supply of an integrated temperature sensor with analog-to-digital converter. A DC-DC boost converter is used to transfer efficiently the energy harvested from a generic radio-frequency rectifier into a charge reservoir, whereas a linear regulator scales the voltage supply to a suitable value for a sensing and conversion circuit. Implemented in a 65 nm CMOS technology, the power management system achieves a measured overall efficiency of 20%, with an available power of 4.5 μW at the DC-DC converter input. The system can sustain a temperature measurement rate of one sample/s with an RF input power of −28 dBm, making it compatible with the power levels available in generic outdoor environments.
Highlights
Energy Harvesting from the Electro-Magnetic (EM) field in the Ultra-High frequency (UHF) range is one of the most promising techniques that will further push the penetration of wireless sensor nodes (WSN) in several environments [1,2,3,4]
In the RF harvesting for WSN contest, a Power Management Unit (PMU) is mandatory to stock the energy harvested from the environment in the reservoir and to supply the circuits of the sensor node
In the former case, the reservoir voltage progressively decreases until the threshold voltage of 1.1 V is reached and the DC-DC converter is disabled, since the energy supplied to the converter is not enough to sustain the sensor with the LDO at the measurement rate of 6.6 Sample/s
Summary
Energy Harvesting from the Electro-Magnetic (EM) field in the Ultra-High frequency (UHF) range is one of the most promising techniques that will further push the penetration of wireless sensor nodes (WSN) in several environments [1,2,3,4]. The system is composed by a DC-DC converter, for the optimization of the energy transfer from the output of the RF rectifier to the accumulator, and a low drop-out linear voltage regulator (LDO), for the generation of the voltage supply of the sensor. The former circuit is an input-driven boost converter designed for intermittent energy sources and is well matched with the RF energy harvesting contest. The control strategy sets the DC-DC input voltage, which corresponds to the output voltage of the rectifier This feature, together with the extreme low power consumption of the whole.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
