A Wireless Power Transmitter With Uniform Power Transfer Coverage

To avoid the performance deterioration caused by the changing placement angle of a receiving antenna, a wireless power transmitter with uniform power transfer coverage is preferred. The utilization of a transmitting antenna with flat-top radiation patterns is the most effective approach. However, the existing antennas with flat-top radiation patterns usually are complex structures and bulky sizes. To mitigate these problems, a rectangular dielectric resonator antenna (DRA) is proposed to obtain flat-top radiation patterns for the first time. Flat-top patterns are realized in both the E and H planes by combining the TE119yand TE133ymodes of a rectangular DRA. For validation, both linearly polarized (LP) and circularly polarized (CP) flat-topped DRAs operating at 5.2 GHz were designed, fabricated, and tested. Reasonable agreement between the measured and simulated results is observed. For the LP design, stable flat-top patterns can be maintained from 5.18 GHz to 5.24 GHz. Across the operating frequency band, the measured 3-dB beamwidths are 86° and 58° in the E and H planes, respectively, with the side lobe levels lower than -13.9 dB. For the CP design, similar flat-top radiation patterns can be found. To demonstrate the effectiveness of the proposed transmitting antenna, the LP design is used to construct a wireless power transmitter, which can provide more power and also uniform power coverage within the desired angular sector.