A High-Efficiency 35GHz Rectenna with compact structure for rectenna arrays

A 35GHz rectenna with high efficiency and compact structure is proposed in this paper. A patch antenna fed by the coupling slot is employed to receive power from free space. The structure of designed rectifier is compact and printed on the bottom side of the antenna. The input low-pass or band-pass filter of the rectifier is removed. Instead, a short ended microstrip line is introduced as a band stop structure to block the harmonics and match the impendence. This circuit configuration highly simplifies the total topology and is suitable for rectenna arrays applications. Furthermore, removing the input filters reduced the insertion loss and thus improved the microwave-to-dc (MW-DC) conversion efficiency. The rectenna is designed, fabricated and measured, a maximum MW-DC efficiency of 53.2% is achieved for a power density of 51.2 mW/cm2 with the dc load 250 $\Omega$ at 35 GHz.