Faculty Publications

An Improved Joint Power Harvesting And Communication Technology For Smartphone Centric Ubiquitous Sensing Applications

Document Type



3.5mm Audio Interface, Frequency Shift Keying, Power Harvester, Smartphone, Ubiquitous Sensing

Journal/Book/Conference Title

2016 13th IEEE Annual Consumer Communications and Networking Conference, CCNC 2016

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Last Page



With the popularization of smartphones, various smartphone centric ubiquitous sensing applications have emerged, which use a smartphone in conjunction with external sensors for data acquisition, processing, display, communication, and storage. Because smartphones do not have a standard data interfaces, many ubiquitous sensing applications use the earphone and the microphone channels of the 3.5mm audio interface for data communications so that they can work with various types of smartphones. The earphone channels of the 3.5mm audio interface can only send AC signal out of a smartphone, and hence DC power needs to be harvested from the earphone channels. Based on frequency shift keying (FSK) modulation scheme, a recent technology developed a joint power harvesting and communication technology to harvest more power from both earphone channels without affecting data communications. However, a transformer is used in the power harvesting circuit, which not only adds the size and the cost of the circuit, but also limits the data rate of the communication. In this paper, we have proposed a novel power harvesting circuit without a transformer. Extensive circuit measurements show that the newly proposed circuit can extract more power than that with a transformer. Furthermore, it allows a reliable communication with much higher data rate from a smartphone to external sensors.

Original Publication Date


DOI of published version



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