Multi-service highly sensitive rectifier for enhanced RF energy scavenging.

Negin Shariati,Wayne S T Rowe,Kamran Ghorbani,James R Scott

doi:10.1038/srep09655

Abstract

Due to the growing implications of energy costs and carbon footprints, the need to adopt inexpensive, green energy harvesting strategies are of paramount importance for the long-term conservation of the environment and the global economy. To address this, the feasibility of harvesting low power density ambient RF energy simultaneously from multiple sources is examined. A high efficiency multi-resonant rectifier is proposed, which operates at two frequency bands (478–496 and 852–869 MHz) and exhibits favorable impedance matching over a broad input power range (−40 to −10 dBm). Simulation and experimental results of input reflection coefficient and rectified output power are in excellent agreement, demonstrating the usefulness of this innovative low-power rectification technique. Measurement results indicate an effective efficiency of 54.3%, and an output DC voltage of 772.8 mV is achieved for a multi-tone input power of −10 dBm. Furthermore, the measured output DC power from harvesting RF energy from multiple services concurrently exhibits a 3.14 and 7.24 fold increase over single frequency rectification at 490 and 860 MHz respectively. Therefore, the proposed multi-service highly sensitive rectifier is a promising technique for providing a sustainable energy source for low power applications in urban environments.

Highlights

Due to the growing implications of energy costs and carbon footprints, the need to adopt inexpensive, green energy harvesting strategies are of paramount importance for the long-term conservation of the environment and the global economy
A dualband radio frequency (RF) energy harvesting using frequency limited dual-band impedance matching has been proposed[20] and the power conversion efficiency (PCE) was shown over a high power range of 0 to 160 Measured DC power (mW), it was only matched at a single input power level (10 dBm)
A rectenna for triple-band biotelemetry communications has been proposed using a triple-band antenna and single frequency rectifier[26]. This rectenna is not suitable for RF energy scavenging due to the low efficiency at lower input power levels. Another triple band rectenna presented an RF-DC efficiency over the input power range of 214 to 120 dBm27, the reflection coefficient results were only evaluated at a single input power level

Summary

Introduction

Due to the growing implications of energy costs and carbon footprints, the need to adopt inexpensive, green energy harvesting strategies are of paramount importance for the long-term conservation of the environment and the global economy. A rectenna for triple-band biotelemetry communications has been proposed using a triple-band antenna and single frequency rectifier[26] This rectenna is not suitable for RF energy scavenging due to the low efficiency at lower input power levels. Another triple band rectenna presented an RF-DC efficiency over the input power range of 214 to 120 dBm27, the reflection coefficient results were only evaluated at a single input power level This rectenna was shown to harvest 7.06 mW of DC power from three sources simultaneously at a high input power level of 110 dBm. A multi-band harvesting system has been proposed where four individual harvesters are designed to cover four frequency bands[28]. The proposed harvesting system has a minimum sensitivity of 225 dBm, whilst in a real environment more sensitive systems are required as the available RF power levels are very low[19]

Methods

Results

Conclusion