A Low-Profile, Wide-Angle, and Bandwidth- Enhanced Rectenna for Radiative Energy Harvesting in the 12 GHz Band

This letter proposes a low-profile rectenna with high gain and wide angular coverage for radio frequency (RF) energy harvesting and wireless power transmission applications. Specifically, a compact traveling-wave antenna array with spatially multiplexed radiation patterns is integrated with a miniature rectifying circuit and a dc power combiner, enabling wide angular coverage and stable dc output power. Our numerical and experimental results show that the proposed rectenna can be robust against changes in the received power and the incident angle (from −65° to 65°, while allowing a wideband operation from 11.5 GHz to 12.5 GHz. The proposed rectenna exhibits a nearly constant dc output voltage of 1.8 V and an RF-to-DC power conversion efficiency of 45% at a power density of 2.86 mW/cm² over a wide range of incident angles and operating frequencies.