Self-Powered Wireless Sensor

TL;DR

This paper presents a novel RF energy harvesting system designed to power wireless sensors by capturing ambient RF signals, demonstrating feasibility at very low power levels and highlighting the importance of zero threshold MOSFETs.

Contribution

The paper introduces a new RF to DC conversion system using zero threshold MOSFETs capable of harvesting ambient RF energy at -37dBm for powering wireless sensors.

Findings

Successfully harvests -37dBm RF energy

Achieves 0.5VDC output for sensor operation

Ambient RF energy fluctuates between -33 to -43dBm

Abstract

This paper develops a novel power harvesting system to harvest ambient RF energy to power a wireless sensor. Harvesting ambient RF energy is a very difficult task as the power levels are extremely weak. Simulation results show zero threshold MOSFETs are essential in the RF to DC conversion process. 0.5VDC at the output of the RF to DC conversion stage is the minimum voltage which must be achieved for the micro-power sensor circuitry to operate. The weakest power level the proposed system can successfully harvest is -37dBm. The measured available power from the FM band has been measured to fluctuate between -33 to -43dBm using a ribbon FM dipole antenna. Ambient RF energy would best be used in conjunction with other forms of harvested ambient energy to increase diversity and dependability. The potential economic and environmental benefits make such endeavors truly worthwhile.