Presentation_RF Energy Harvesting Chip Powered Sensor Node

Paper Summary

Paper Name RF Energy Harvesting Chip Powered Sensor Node
Published in Electronics, Circuits and Systems (ICECS), 2016 IEEE International Conference
Authors Younus Syed; Bharat G. Hegde; T. V. Prabhakar; M. Manjunath; K. J. Vinoy
Paper Overview The development of battery-less wireless sensor mote powered by an RFID reader, which can communicate the sensor data to multiple BLE enabled devices at a single instant.

  • Integrating the RF Energy Harvesting circuits (RF-DC and DC-DC Converters) onto a die area of size 0.75 mm sq.
  • RFEH chip was able to harvest energy from input power levels -12 dBm.
  • The system was successfully run at minimum RF power level of -8 dBm.
System Model

(Fig. 1. System architecture)

(Fig. 2. Block Diagram of Chip)

(Fig. 3. RF to DC Converter Implemented on Chip)

(Fig. 4. A Stage of Implemented DC-DC Converter)

Design aspects of the RFEH chip
  •  RF-DC Converter : utilize the Square-law V-I characteristics of MOS transistor, they substituted MOS for Schottky in practice.
  • Switched Capacitor DC-DC Converter : Two types of clocks are to be generated, one overlapping set to drive NMOS devices and a non-overlapping set to drive PMOS devices, this is to reduce reversion losses. Five such stages were cascaded, to boost the minimum output voltage of RF-DC.
  • Voltage Limiter : Employing a feedback circuit around DC-DC, to control the output voltage.
  • Power on Reset : Generates a reset signal, it can be used to enable an LDO or give an interrupt to a micro-controller.