Efficiency Improvement of a Microwave Power Transfer System with an Integrated Flat-Top Beamwidth Antenna and Rectifier

In this letter a novel rectenna featuring fully integrated rectification within a uniformly radiating antenna for a microwave power transmission system is presented. The proposed structure consists of a magneto-electric ring dipole antenna fed by a pair of parallel lines and a class-F rectifier. For compactness and a low profile, the class-F rectifier was fully integrated into the backside of the antenna’s feeding mechanism while maintaining its uniform power radiation characteristics and impedance matching between the rectifier and antenna at 5.8 GHz. The proposed structure’s overall dimensions are 0.97λ<sub>0</sub> × 0.97λ<sub>0</sub> × 0.27λ<sub>0</sub>, and it has been fabricated and measured. The measured results show that the proposed rectenna has a peak conversion efficiency of 79% at 5.8 GHz. Moreover, the proposed rectenna can maintain a uniform voltage of 1.9 V in the diameter range of 50 mm. With its structure and uniform power radiation, the proposed integrated rectenna is well suited for a microwave power transmission system.