Quad-Band Rectenna for Ambient Radio Frequency (RF) Energy Harvesting

Area of Science:

• Electrical Engineering
• Wireless Communication
• Energy Harvesting

Background:

• Ambient radio frequency (RF) power is abundant in urban and semi-urban areas, presenting an opportunity for wireless energy scavenging.
• Existing RF harvesting technologies often face limitations in efficiency and bandwidth coverage.

Purpose of the Study:

• To design and develop a high-efficiency quad-band rectenna for scavenging ambient RF energy.
• To analyze ambient RF power characteristics and utilize the data for optimizing the harvester design.

Main Methods:

• A quad-band rectenna was designed, incorporating a novel impedance matching network (IMN) with an additional L-network for improved efficiency at low input power densities.
• A dual-polarized multi-frequency bow-tie antenna with a wide bandwidth and miniature size was developed using specific structural enhancements.
• RF survey data was analyzed to tailor the harvester's frequency coverage to prevalent mobile phone and wireless local area network (WLAN) bands.

Main Results:

• The designed rectenna covers key frequency bands (0.8-2.5 GHz), including those used by mobile phones and WLANs.
• The optimized impedance matching network achieved a maximum RF-to-DC conversion efficiency of up to 48% at an optimal resistance of 1-10 kΩ.
• Ambient RF energy harvesting yielded DC voltages of 124.3 mV (indoor) and 191.0 mV (outdoor).

Conclusions:

• The developed quad-band rectenna effectively scavenges ambient RF energy across multiple frequency bands.
• The harvester demonstrates potential for powering low-power sensors and wireless applications using harvested RF energy.
• The design offers a promising solution for efficient wireless power transfer in diverse environments.