Radiation Pattern Reshaping of a Three-band Rectenna for Wireless Power Transmission

In this article, a three-band rectenna for wireless power transmission is designed, which consists of a slot antenna using folded slot and a three-band rectifier, operating at 2.45 GHz, 4.2 GHz, 5.8 GHz three frequency bands. First, by using folded slots, the radiation waveforms of the slot antenna’s $\lambda$-modes and $2 \lambda$-modes are reshaped to achieve stable radiation of the antenna in the upper and lower spaces. Then, a three-band rectifier was designed by using two diode branches with different impedances. The conversion efficiency of the rectifier at three frequencies is greater than $50 \%$ in the range of 4 dBm to 15 dBm, and the maximum conversion efficiency is $70 \%, 70 \%$, and $69 \%$ respectively.