This paper discusses a comparison between 3-element and 5-element Yagi-Udaantenna to find out the best antenna for power harvesting from available RF waves in urbanareas. The antenna will extract available RF waves from environment. The harvested energyfrom the chosen antenna, which of very low magnitude is later amplified to a suitable valuefor the use in consumer appliances, especially for mobile devices. It will increase the mobilityof the device and allow using the unused electromagnetic wave for daily purposes, thusreducing the pressure on national power grid in a broad sense. Additionally, this paperdiscusses the antenna structure and methods for extracting DC power from electromagneticradiation.