Modular and Reconfigurable Rectenna Unitcells with Beam-Forming Properties

This paper presents a modular and reconfigurable rectenna unitcell (RU) made up of an antenna, a rectifier and radiofrequency (RF) power combiners intended to form a scalable and adaptative beam-forming network, for autonomous passive tracking or RFID monitoring applications. The reconfigurable rectenna unitcell allows a dual mode operation thanks to both RF and DC possible combinations of multiple rectenna unitcells. On the one hand, the passive beam-forming operation, coming from the RF combination of multiple rectenna unitcells provides oriented communication or localization capabilities. On the other hand, the series DC connection of RF isolated rectenna unitcells delivers DC power to the system with high output voltage under low RF power densities. Prototypes of 4-edges rectenna unitcells are designed in the 2.4 GHz band. The operation of one individual RU is demonstrated, and it is shown that multiple RUs are suitable for RF energy harvesting, multiple-tag communication and tag localization.