A Scalable, Wide-Angle Metasurface Array for Electromagnetic Energy Harvesting

Area of Science:

• Electromagnetics
• Materials Science
• Electrical Engineering

Background:

• Wireless communication technologies, such as Wi-Fi, generate significant ambient electromagnetic (EM) energy.
• Efficient harvesting of this ambient EM energy is crucial for powering low-power electronic devices and enabling the Internet of Things (IoT).
• Metasurfaces offer unique capabilities for manipulating EM waves, making them promising for energy harvesting applications.

Purpose of the Study:

• To design and demonstrate a metasurface array for effective electromagnetic energy harvesting specifically within Wi-Fi frequency bands.
• To integrate a rectifier circuit and load resistor with the metasurface array for direct current (DC) energy generation.
• To validate the proposed design through the fabrication and testing of a prototype.

Main Methods:

• A metasurface array was designed, comprising interconnected unit cells forming energy transfer channels.
• A single series diode rectifier circuit and a load resistor were coplanarly integrated at the channel terminals.
• A 5x7 prototype of the metasurface array was fabricated and tested in an anechoic chamber.

Main Results:

• The metasurface array effectively transfers and concentrates incident EM power through its interconnected channels.
• The integrated rectifier circuit successfully converted radio frequency (RF) energy from Wi-Fi bands into DC power.
• The fabricated prototype achieved a maximum RF-to-DC conversion efficiency of 72% at 5.9 GHz with an input power of 7 dBm.

Conclusions:

• The developed metasurface array is a viable solution for efficient electromagnetic energy harvesting from Wi-Fi bands.
• The integrated design facilitates the concentration of EM power and its subsequent rectification for DC energy harvesting.
• The experimental results confirm the design's rationality and demonstrate its potential for practical wireless power transfer applications.