IEEE JOURNAL ON EMERGING AND SELECTED TOPICS IN CIRCUITS AND SYSTEMS, VOL. 2, NO. 1, MARCH 2012
Design Optimization and Implementation
for RF Energy Harvesting Circuits
Prusayon Nintanavongsa, Student Member, IEEE, Ufuk Muncuk, David Richard Lewis, and Kaushik Roy Chowdhury, Member, IEEE
Abstract—A new design for an energy harvesting device is proposed in this paper, which enables scavenging energy from radiofrequency (RF) electromagnetic waves. Compared to common alternative energy sources like solar and wind, RF harvesting has the least energy density. The existing state-of-the-art solutions are effective only over narrow frequency ranges, are limited in efﬁciency response, and require higher levels of input power. This paper has a twofold contribution. First, we propose a dual-stage energy harvesting circuit composed of a seven-stage and ten-stage design, the former being more receptive in the low input power regions, while the latter is more suitable for higher power range. Each stage here is a modiﬁed voltage multiplier, arranged in series and our design provides guidelines on component choice and precise selection of the crossover operational point for these two stages between the high (20 dBm) and low power ( 20 dBm) extremities. Second,
we fabricate our design on a printed circuit board to demonstrate how such a circuit can run a commercial Mica2 sensor mote, with accompanying simulations on both ideal and non-ideal conditions for identifying the upper bound on achievable efﬁciency. With a simple yet optimal dual-stage design, experiments and characterization plots reveal approximately 100% improvement over other existing designs in the power range of 20 to 7 dBm.
Index Terms—Optimization, power efﬁciency, radio-frequency (RF) energy harvesting circuit, Schottky diode, sensor, voltage multiplier, 915 MHz.
ITH the growing popularity and applications of largescale, sensor-based wireless networks (e.g., structural health monitoring, human health monitoring, to name a couple), the need to adopt inexpensive, green communications strategies is of paramount importance. One approach is to deploy a network comprising self-powered nodes, i.e., nodes that can harvest ambient energy from a variety of natural and man-made sources for sustained network operation . This can instrument potentially leading to signiﬁcant reduction in the costs associated with replacing batteries periodically. Moreover, in some deployments, owing to the sensor location, battery replacement may be both practically and economically infeasible, or may involve signiﬁcant risks to human life. Thus, there is a strong moti-
Manuscript received October 15, 2011; revised January 12, 2012; accepted January 30, 2012. Date of publication February 28, 2012; date of current version April 11, 2012. This material is based upon work supported by the U.S. National Science Foundation under Grant CNS-1143662.
The authors are with the Department of Electrical and Computer Engineering, Northeastern University, Boston, MA 02115 USA (e-mail: email@example.com. edu; firstname.lastname@example.org; email@example.com; firstname.lastname@example.org). Color versions of one or more of the ﬁgures in this paper are available online at http://ieeexplore.ieee.org.
Digital Object Identiﬁer 10.1109/JETCAS.2012.2187106
Fig. 1. Ambient RF energy harvesting.
vation to enable an off-the-shelf wireless sensor network (WSN) with energy harvesting capability that would allow a sensor to replenish part or all of its operational costs, thereby taking the ﬁrst steps towards realizing the vision of a perennially operating network.
The concept of wireless energy harvesting and transfer is not new, rather it was demonstrated over 100 years ago by Tesla
. In recent times, RFID technology is a clear example of
wireless power transmission where such a tag operates using
the incident radio-frequency (RF) power emitted by the transmitter . However, there are...