A 3-D Folded Dipole Antenna Array for Far-Field Electromagnetic Energy Transfer

We present the concept and design of vertically stacked electromagnetic energy-harvesting system using folded dipole antennas. The proposed system is composed of stacked rectenna arrays or panels that are connected in various ways to channel the collected ac power to a single dc load. We show through experiments that by vertically stacking rectenna panels, the power collected per footprint is enhanced significantly. In fact, an improvement of up to 5 times is achieved in comparison to a single panel occupying the same two-dimensional footprint.