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 pattern is the most effective approach. However, the existing antenna configurations usually have 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 TE^y₁₁₉ and TE^y₁₃₃ modes 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 characteristics can be found. To demonstrate the effectiveness of the proposed antenna, the LP design was used to construct a wireless power transmitter, which provides more uniform power coverage within the desired angular sector.