Custom IC for Ultralow Power RF Energy Scavenging

• Published in: IEEE transactions on power electronics 2011-06, Vol.26 (6), p.1620-1626
• Main Authors: Thurein Paing, Falkenstein, E. A., Zane, R., Popovic, Z.
• Format: Article
• Language: English
• Subjects: Applied sciences; Batteries; Circuit properties; Converters; DC-DC; Design. Technologies. Operation analysis. Testing; Electric currents; Electric power; Electric, optical and optoelectronic circuits; Electrical engineering. Electrical power engineering; Electronic circuits; Electronic equipment and fabrication. Passive components, printed wiring boards, connectics; Electronics; Energy harvesting; Exact sciences and technology; Integrated circuits; Low power electronics; Oscillators; Power electronics, power supplies; Radio frequency; resistor emulation; RF energy scavenging; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Signal convertors; ultralow power
• ISSN: 0885-8993; 1941-0107
• DOI: 10.1109/TPEL.2010.2096475

This letter presents a custom IC that provides an efficient interface between an ultralow power RF rectifying antenna (rectenna) power source and a microbattery for maximum power scavenging. The energy scavenger IC operates a boost converter in pulsed fixed-frequency discontinuous conduction mode to present a positive resistance to the rectenna. It uses current-starved circuitry, a nonoverlapping gate drive, and a subthreshold current source to achieve a nominal supply current in the 200-nA range for V DD = 2.5 V. Experimental results are given with the IC scavenging energy from a 1.93-GHz patch rectenna to a battery with voltages ranging from 2.5 to 4.15 V. Overall conversion efficiency including all control losses is demonstrated at over 35% at an input power of just 1.5 μW and at over 70% at input power levels over 30 μW. The IC is fabricated in a 5-V, 0.35-μm CMOS process. Although the IC was designed for RF energy scavenging, the low-power boost converter can be applied to other power sources such as wind, vibration, and temperature.