A Self-Powered Hybrid Energy Scavenging System Utilizing RF and Vibration Based Electromagnetic Harvesters

Ulusan H., Gharehbaghi K., Zorlu O., Muhtaroglu A., KÜLAH H.

15th International Conference on Micro and Nanotechnology for Power Generation and Energy Conversion Applications (PowerMEMS), Massachusetts, United States Of America, 1 - 04 December 2015, vol.660 identifier identifier

  • Publication Type: Conference Paper / Full Text
  • Volume: 660
  • Doi Number: 10.1088/1742-6596/660/1/012023
  • City: Massachusetts
  • Country: United States Of America
  • Middle East Technical University Affiliated: Yes


This study presents a novel hybrid system that combines the power generated simultaneously by a vibration-based Electromagnetic (EM) harvester and a UHF band RF harvester. The novel hybrid scavenger interface uses a power management circuit in 180 nm CMOS technology to step-up and to regulate the combined output. At the first stage of the system, the RF harvester generates positive DC output with a 7-stage threshold compensated rectifier, while the EM harvester generates negative DC output with a self-powered AC/DC negative doubler circuit. At the second stage, the generated voltages are serially added, stepped-up with an on-chip charge pump circuit, and regulated to a typical battery voltage of 3 V. Test results indicate that the hybrid operation enables generation of 9 mu W at 3 V output for a wide range of input stimulations, which could not be attained with either harvesting mode by itself. Moreover the hybrid system behaves as a typical battery, and keeps the output voltage stable at 3 V up to 18 mu W of output power. The presented system is the first battery-like harvester to our knowledge that generates energy from two independent sources and regulates the output to a stable DC voltage.