High-Efficiency X-Band Rectenna Design for Wireless Power Transmission in Drone Applications

Wireless Power Transmission (WPT) has emerged as a promising technology for applications such as solar power satellites and high-altitude platforms, including UAVs, drones, and aircraft, with ongoing advancements in microwave-based systems enhancing efficiency and performance. Drones require lightweight, compact antennas for effective WPT, making microstrip patch arrays on low-density substrates an ideal choice. To overcome the limited gain of small antennas, a quasi Yagi-Uda design is implemented, offering a balanced solution with moderate gain, wide beamwidth, and compact size. The antenna is fabricated on a 10 mil Rogers RT/duroid 5880 substrate, known for its low dielectric constant and ultra-low loss tangent, making it suitable for X-band drone applications. The design includes a driven dipole, director, reflector, and additional directors to enhance gain, achieving beamwidths of 42° in the E-plane and 56° in the H-plane with a gain of 8.75 dBi. On the rectifier side, efficient power conversion is critical, especially at higher input levels where PCE typically decreases. A two-section quarter-wave transformer, low-pass filter, and DC pass filter are integrated to improve impedance matching and bandwidth. The proposed rectifier achieves peak PCE values between 53% and 57% for input powers of 20-50 mW, with over 50% PCE across a 0.75 GHz bandwidth and more than 40% across 1.75 GHz. The system's effectiveness is validated by successfully powering a Humidity, Temperature, and Clock (HTC) sensor using an X-band microwave input, demonstrating its potential for efficient wireless power delivery in drone-based applications.