A W-Band 2 × 2 Rectenna Array With On-Chip CMOS Switching Rectifier and On-PCB Tapered Slot Antenna for Wireless Power Transfer.

This article presents a $W$ -band rectenna unit that incorporates a novel CMOS switching rectifier and a print tapered slot antenna. The operation principle of the switching rectifier is analyzed. The proposed rectifier topology shows improved reliability, and it utilizes the body-diode effect (BDE) to improve power conversion efficiency (PCE). Besides, a high-gain $W$ -band antipodal linearly tapered slot antenna is implemented on PCB to improve the overall efficiency. In order to demonstrate the utility of the proposed rectenna unit for large-scale rectenna array, a $1\times 2$ (parallel) and $2\times 2$ (series-parallel) rectenna arrays in 40-nm bulk CMOS technology and PCB process have been implemented. The switching rectifier achieves a peak PCE of 45.8% at 94GHz with improved reliability. Occupying only 0.0756 mm2, the overall PCEs of the rectenna unit and the $2\times 2$ rectenna array are 25% and 23%, delivering 5.6- and 20-mW output dc power, respectively, at 90-mW/cm2 incident power density. The proposed rectifier and rectenna array achieve the highest PCE among recently reported $W$ -band rectifiers and rectenna arrays with different technologies. [ABSTRACT FROM AUTHOR]