High-efficiency electromagnetic energy harvesting using double-elliptical metasurface resonators

Area of Science:

• Applied Physics
• Electromagnetics
• Metamaterials

Background:

• Ambient electromagnetic (EM) energy harvesting is crucial for powering low-power devices.
• Existing harvesting systems often suffer from impedance mismatch and low efficiency.
• Metasurfaces offer unique electromagnetic properties for advanced applications.

Purpose of the Study:

• To introduce a novel metasurface (MS) based electrically small resonator for enhanced ambient EM energy harvesting.
• To design a resonator with input impedance matched to free space for efficient power absorption.
• To maximize harvesting efficiency by channeling power from all array resonators to a single load.

Main Methods:

• Design and simulation of a metasurface unit cell composed of double-elliptical cylinders.
• Analysis of the unit cell's absorption and harvesting efficiency under normal and oblique incidence.
• Integration of a 4x4 array of resonators with a corporate feed network to channel power to a single load.

Main Results:

• The MS unit cell demonstrated near-perfect absorption (90%) in the 5.14-5.5 GHz range with a 21% fractional bandwidth.
• High harvesting efficiency was maintained at incident angles up to 60 degrees.
• The 4x4 array with a corporate feed network achieved an overall radiation-to-AC efficiency of approximately 90%.

Conclusions:

• The developed metasurface resonator is highly effective for ambient electromagnetic energy harvesting.
• The design overcomes limitations of previous works by consolidating power to a single load.
• This technology shows significant promise for practical energy harvesting applications.