Novel broadband Yagi-Uda antenna for ambient energy harvesting

The main challenge for the far field energy harvesting is to overcome the losses due to the long distance between the transmitter and the harvesting location. To compensate for the path losses, antenna arrays or high gain antennas should be used at the receiving part. This paper introduces a novel broadband high gain Yagi-Uda antenna. The design is based on integrating a wide-band strip dipole into a Yagi-Uda antenna. The antenna consists of a reflector and a single director placed nearby the driven dipole. The length of the director, the distance between the feed and the director, and the distance between the feed and the reflector are investigated and optimized in order to reach the widest bandwidth possible for receiving DTV broadcasting signals (475-810 MHz). Detailed design optimization steps, return loss, antenna gain and front-to-back ratio for the new configuration are discussed. The antenna operating band reached 61.2 % in 2.0:1.0 VSWR, and consequently overcame the state of the art by an increased bandwidth of 11.2 %. The simulated results are validated by measurements.