Feasibility study on ambient RF energy harvesting for wireless sensor network

Abstract

RF energy harvesting holds a promising future for generating a small amount of energy to potentially power on a low power device such as wireless sensor network especially in an urban country like Singapore. Due to path loss and restriction on permissible transmission power; the RF power available to the input of the RF energy harvesting system is relative low. In this work, we present a study of ambient RF energy harvesting. We also explore to determine whether another emerging technology wireless power transfer can be integrated with RF energy harvesting. A measurement of the ambient RF power density on GSM 900 and GSM 1800 bands in Nanyang Polytechnic of Singapore is presented. From our conclusion, the harvested energy is not able to directly power the wireless sensor network; however the harvested energy can be stored in a super-capacitor and over some time it can be used to power on the wireless sensor network. So, is RF energy harvesting ever going to become a practical reality? The answer is a cautious yes.