Folded Patch Antenna on Paper for RF Energy Harvesting and Sensing Applications

The design of antennas on cellulosic flexible materials such as paper can be very challenging because of the limited thickness and the high losses in the Radio Frequency (RF) domain. In this paper, a novel patch antenna with an origami structure is proposed to address the null radiation efficiency obtained with the conventional paper-based structure. As the electromagnetic waves mostly travel in the air, ideal conditions such as no loss and a low dielectric constant allow for the asymptotic value of directivity of microstrip antennas to be reached with a 63 % experimental radiation efficiency. This flexible antenna can be used for RF energy harvesting or sensing applications due to the sensitivity of paper on atmospheric conditions.