A 3D Rectenna with All-Polarization and Omnidirectional Capacity for IoT Applications
A 3D rectenna with all-polarized and omnidirectional capacity is presented in this paper. The proposed rectenna is composed of six dual-linear polarized (DLP) rectennas, in a hexahedron. Each DLP cell is composed of a DLP antenna, a 90° hybrid, and a modified rectifier. The 90° hybrid and modified rectifier are employed to reallocate received powers between two ports of DLP antenna, and the topology can maintain high RF-to-DC power conversion efficiency when the polarization of incident wave is uncertain or varying. The proposed 3D rectenna can harvest RF power all round efficiently. With a measured power density of 355 µW/cm², the output dc power maintains above 1.2 mW when the tile angle varies from 0° to 360° perpendicular to the surface of rectenna, and the maximum dc power is 2.8 mW.