Microstrip antenna designs for RF energy harvesting

In recent years, alternate energy sources has become essential as the demand for power increases. In the last energy decades energy obtained from external sources such as thermal energy, solar power, wind energy, and RF energy has been in use for various purposes. To provide unlimited energy for the lifespan of electronic devices, energy harvesting uses inexhaustible sources with no adverse environmental effect. This paper focuses on RF energy harvesting. The receiving antenna captures the RF energy from surrounding sources, such as nearby mobile phones, wireless LANs (WLANs), FM/AM radio signals, broadcast television signals and rectified into a usable DC voltage. One possibility to overcome their power limitations is to extract (harvest) energy from the environment to either recharge a battery, or even to directly power the electronic device. To meet various objectives in last few years, several antenna designs of rectenna have been proposed for use in RF energy harvesting,. Among the other antennas, microstrip patch antennas are widely used because of their low profile, light weight, and planar structure. This paper presents several methods to design and energy harvesting device depending on the type of energy available and also presents microstrip path structural rectenna are explains RF signal harvester for powering low consumption electrical devices.