High Efficiency RF Energy Harvester for IoT Embedded Sensor Nodes

The lifetime of battery-operated sensor platforms (i.e., sensor nodes) is a critical issue. The replacement of their batteries is quite a challenging task if these platforms are deployed for detecting events in inaccessible geographical areas (e.g., forest). This paper describes an optimized RF energy harvester/scavenger (consisting of an antenna, impedance matching circuit and rectifier) for energizing low-power sensor platforms (electronic systems). Few nonmatched rectifiers (using HSMS-285X Schottky diodes) are fabricated to characterize the input impedance for different sets of parameters. After characterization a proper impedance matching circuit is integrated for the maximum power transfer from antenna to rectifier. It is shown that a single stage of RF rectifier is enough to produce output voltage of 1.8[Formula: see text]V. Very few realizations of RF energy harvester are reported in the literature under 2.4[Formula: see text]GHz ISM band category. Furthermore, high-gain microstrip patch array antennas are fabricated to capture the maximum power from the surroundings. The maximum harvesting range of 0.92[Formula: see text]m is obtained at 27[Formula: see text]dBm transmitting power level.

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A High-Efficiency and Wide-Input Range RF Energy Harvester Using Multiple Rectenna and Adaptive Matching

Energies ◽

10.3390/en13051023 ◽

2020 ◽

Vol 13 (5) ◽

pp. 1023

Author(s):

Hamed Abbasizadeh ◽

Arash Hejazi ◽

Behnam Samadpoor Rikan ◽

Sang Yun Kim ◽

Jongseok Bae ◽

...

Keyword(s):

Radio Frequency ◽

Energy Harvester ◽

High Efficiency ◽

Power Level ◽

Schottky Diodes ◽

Smart Devices ◽

Dc Voltage ◽

Input Range ◽

Rf Energy ◽

Rf Energy Harvester

In this paper, a Radio Frequency (RF) energy harvester (EH) system for Internet of Things (IoT)-related applications is presented. The proposed EH architecture operates at 5.2 GHz band and utilizes multiple rectenna. This approach enhances the efficiency of the whole system over a wide dynamic RF input range. In the presented circuit, configuration of the rectenna is controlled by Field-Programmable Gate Array (FPGA) with respect to the input power level of the received RF input signal. In addition, an automatic adaptive matching based on the configuration of the rectenna, level of the received signal, and load current adjusts the matching network. The rectenna is realized through the Radio Frequency-Direct Current (RF-DC) converter composed of two Schottky diodes and generates the output DC voltage. Finally, a buck-boost converter provides the flattened and fixed voltage for the IoT and wearable devices. The 5.2 GHz band reconfigurable system demonstrates 67% high efficiency and 6.1 V output DC voltage where the power level of RF input is +20 dBm. The main application of the proposed structure is for charging wearable smart devices such as a smart watch and bracelet.

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A 5.8 GHz Low-Power Energy Harvester for RF Wireless Power Transfer Systems

Journal of Circuits System and Computers ◽

10.1142/s0218126620500760 ◽

2019 ◽

Vol 29 (05) ◽

pp. 2050076

Author(s):

Mariem Kanoun ◽

David Cordeau ◽

Jean-Marie Paillot ◽

Hassene Mnif ◽

Mourad Loulou

Keyword(s):

Low Power ◽

Power Management ◽

Design Methodology ◽

Energy Harvester ◽

Input Power ◽

Sensor Nodes ◽

Wireless Power ◽

Simulation Results ◽

Rf Energy ◽

Rf Energy Harvester

This paper presents the design and implementation of an RF energy harvester system at 5.8[Formula: see text]GHz for low-power wireless transmission applications. The potential application of the proposed system is to wirelessly power sensor nodes. First, a design methodology of the rectifier based on a theoretical approach is presented. The simulation results show an excellent correlation with the theoretical ones, proving the accuracy of the proposed design methodology. A prototype is fabricated and the simulation results are validated by the measurements. Then, the rectenna is combined to a commercial power management circuit and a load which emulates the behavior of a sensor. The power management circuit boosts and regulates the output DC voltage as well as stores the collected energy into a capacitor. Finally, the complete system is experimentally tested and excellent performances are demonstrated. The efficiency of the RF energy harvester is 24% at [Formula: see text]10[Formula: see text]dBm input power and 47% at [Formula: see text]5[Formula: see text]dBm input power which are the highest reported measured efficiencies at this frequency and at those power levels. The complete rectenna system is able to harvest 4.62[Formula: see text]mJ in 40 s and 192[Formula: see text]s for [Formula: see text]6[Formula: see text]dBm and [Formula: see text]10[Formula: see text]dBm input power, respectively allowing us to power wirelessly low-power electronic devices.

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