7.6 µW Ambient Energy Harvesting Rectenna from LTE Mobile phone Signal for IoT Applications

The paper presents a structure of an efficient RF energy harvesting (RFEH) rectenna that harvests available RF signals in the environment for the Internet of Thing (IoT) applications. In the system, the dynamic threshold MOSFET (DTMOS) structure is applied to a cross-coupled rectifier (CCR) in 65nm Silicon on Thin Buried Oxide (SOTB) technology to improve the efficiency of the rectifier. Besides, the RFEH system is designed to have a moderate Q factor and wide bandwidth to effectively harvest modulated signals in an ambient environment. A Yagi antenna is utilized to increase the RF input power of the system. The proposed rectenna is evaluated with an LTE 950 MHz band mobile phone signal from a base station in various measurement conditions. Experimental results show that the system can generate 3.5 µW DC power at an indoor condition, and 7.6 µW at an outdoor condition. The proposed system reaches the highest performance in comparison with other RFEH systems in the literature. The rectenna is suitable for utilizing ambient RF energy harvesting for IoT applications.