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 × 2 (parallel) and 2 × 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 mm
²
, the overall PCEs of the rectenna unit and the 2 × 2 rectenna array are 25% and 23%, delivering 5.6and 20-mW output dc power, respectively, at 90-mW/cm
²
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.