2 x 2 textile rectenna array with electromagnetically coupled microstrip patch antennas in the 2.4 GHz WiFi band

The development of e-textiles is fostering research in wireless energy transmission. This paper presents a purely textile 2.4 GHz WiFi band 2 x 2 rectenna array for RF energy harvesting. It utilizes the electromagnetically coupled microstrip patch antenna topology and a simple and precise construction method that provides a good performance repeatability to create multilayer microstrip textile patch antennas. The rectifier is implemented with Schottky diodes and it takes the voltage doubling configuration. An average DC power of 1,1 mW was measured for 14 mu W/cm(2) of RF input power density, while the end-to-end average power conversion efficiency (PCE) measured was 31%. The characterization of the end-to-end PCE was evaluated considering the physical size of the prototype to make the comparison with other designs easier. Measurements in a real WiFi scenario were also performed, demonstrating its feasibility for feeding e-textiles.