Harvesting RF Energy- A Review

There is a demand of power at remote locations for many applications such as charging of batteries for WSN. Due to advancement in technology, many devices operate at low power level. The RF energy can be harvested and fed to these devices on board. RF signal is available globally and energy can be harvested from this signal. It is available at all times and can be used as source of energy for low power devices. RF harvesting unit consists of three modules, Antenna, Matching network and Rectifier circuit. This paper presents an overview of each stage of RF harvesting architecture. The paper introduces designed antennas, factors affecting the different parameters of antenna like bandwidth, gain and efficiency. Design of antenna with miniaturization, harmonic rejection and frequency selectivity is explained. The comparative study of matching network such as L type, π type and microstrip line is described for maximum power transfer and different rectifier circuits for RF to DC conversion are discussed