Design and testing of RF energy harvesting module in GSM 900 band using circularly polarized antenna

The energy harvesting techniques form an encouraging alternative to existing energy resources. The increased use of mobile phones and installation of cell phone towers have made the availability of free radio frequency (RF) energy near the transmission towers and in the ambient environment. Due to the abundance of RF energy, the RF energy harvesting (RFEH) is found as an attractive possibility. The harvested power may be stored to power sensor networks and also used for recharging the batteries of wireless devices like mobile phones. However, there are challenges in designing the RFEH module i.e. rectenna, which consists of antenna, appropriate circuitry to convert the captured electromagnetic (EM) energy to DC power. This paper presents the design of an efficient yet simple RFEH module. The module consists of a slot antenna with circular polarization and bridge rectifier. The measured results for the prototype in the laboratory environment are also presented.