A foldable textile-based broadband archimedean spiral rectenna for RF energy harvesting

In this work, a new Broadband RF energy harvesting system is introduced, employing an Archimedean spiral antenna, a 6-stage voltage doubler, and a DC-DC converter. The proposed system operates over a frequency range from 0.9 GHz to 4 GHz. A balun is used to feed the antenna and is connected to the rectifying circuit via an SMA connector. The spiral antenna is fabricated using Conductive Shieldit super and Felt for the substrate. Also, other textile materials were used such as: Stainless steel threads for the conductive layer and Fleece for the substrate. The measured rectified DC voltage had a peak of 1.5V when testing outdoors, and was 0.5 V when testing indoors. The overall system efficiency was approximately 30%.