A Rectifier With Less Sensitivity to the Incident Angle of Incoming Waves Based on Quadrature Coupler

This brief presents a radio frequency (RF) rectifier with wide-incident-angle (WIA) of incoming waves based on quadrature coupler (QC). The proposed rectifier mainly consists of a QC, two identical sub-rectifiers (Rect(A) and Rect(B)) and a direct current (DC) power combining circuit. Two RF power sources (RF1 and RF2) with identical power and a phase difference (Delta phi) are connected to the input and isolated ports of the QC. In addition, Rect(A) and Rect(B) are connected to the two output ports of the QC. Then, the DC output of RectA and RectB are combined by a DC power combining circuit. Finally, the obtained DC power is transmitted to the DC load. Theoretical analysis is carried out. For validation, a rectifier operating at 2.45 GHz is designed, fabricated and measured. The measured results show that the peak RF-to-DC power conversion efficiency (PCE) is 73.4 % and the PCE varies from 64.7 % to 73.4 % when Delta phi varies in the range of 0 degrees-360 degrees. These results demonstrated the effectiveness of the proposed scheme in designing WIA rectifier.