Metamaterial-Integrated High-Gain Rectenna for RF Sensing and Energy Harvesting Applications.

Area of Science:

• Electromagnetics and Metamaterials
• Antenna Engineering
• Energy Harvesting

Background:

• Rectennas are crucial for wireless power transfer and energy harvesting.
• Metamaterials offer unique electromagnetic properties for antenna enhancement.
• Existing rectenna designs often face limitations in gain and efficiency.

Purpose of the Study:

• To develop a high-gain rectenna integrated with a metamaterial (MTM) superstrate.
• To enhance RF sensing and energy harvesting capabilities at the 2.45 GHz ISM band.
• To investigate the performance improvements offered by the MTM superstrate approach.

Main Methods:

• A three-layered rectenna structure was designed, incorporating an MTM superstrate, a patch antenna, and a rectifier circuit.
• Parametric analysis was conducted to optimize the MTM unit cell's near-zero property.
• The impact of the number of MTM unit cells on rectenna performance was studied.

Main Results:

• The MTM-integrated rectenna achieved a measured gain of 11.87 dB, a 6.12 dB improvement over a standard patch antenna.
• Maximum RF-to-DC conversion efficiency reached 78.9%, a significant increase from 39.2%.
• Output DC power improved by a factor of 8.96, from 0.7 mW to 6.27 mW.

Conclusions:

• The MTM superstrate effectively enhances rectenna gain and RF-to-DC efficiency.
• The integrated design offers low complexity and scalability for various applications.
• This technology shows great potential for practical RF energy harvesting in IoT environments.