Title
A Thermal/RF Hybrid Energy Harvesting System With Rectifying-Combination and Improved Fractional-OCV MPPT Method
Abstract
This paper presents a thermal/RF hybrid energy harvester. The energy harvesting system can scavenge energy from a thermoelectric generator (TEG) and a radio-frequency (RF) energy source simultaneously, and deliver the combined power to a single load. Two techniques are employed in the system to increase the end-to-end efficiency; the rectifying-combination technique is proposed to eliminate the power loss associated with a dedicated AC-DC converter before the combiner and an improved fractional open-circuit voltage (FOCV) maximum power tracking (MPPT) is considered for a high average efficiency. A dynamic power path control extracts the maximum RF power from a cross-coupled differential rectifier, and also behaves as an AC/DC energy combiner. The thermal/RF harvester system achieves a measured peak end-to-end power conversion efficiency (PCE) of 63.4%. The shorter sampling time of 26ms every 16s for the proposed FOCV MPPT method reduces the long charging tail required to refresh the sampling capacitor, resulting in a an improved average efficiency of 82.2% for the thermal harvester. Fabricated in 0.18 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\mu \text{m}$ </tex-math></inline-formula> CMOS technology, the prototype operates at a thermal input voltage ranging from 40 mV to 400 mV and an RF power from −18 dBm to −3 dBm and delivers an output voltage of 1.8 V. The total area of the fabricated circuit prototype is 1.22 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> .
Year
DOI
Venue
2020
10.1109/TCSI.2020.2982403
IEEE Transactions on Circuits and Systems I: Regular Papers
Keywords
DocType
Volume
Energy harvesting,Radio frequency,Capacitors,Maximum power point trackers,Transducers,Switches,Voltage control
Journal
67
Issue
ISSN
Citations 
10
1549-8328
3
PageRank 
References 
Authors
0.41
0
3
Name
Order
Citations
PageRank
Zemin Liu16412.71
Yu-Pin Hsu252.13
Mona Mostafa Hella36814.51