RF Energy Harvesting - - Literature review Example

Energy harvesting allows for recycling and harvesting of wasted ambient electromagnetic energy to cater for the energy requirements of devices suing wireless technology such as wireless personal area networks (WPANs), wireless local networks (WLANs) and Cellular networks. In RF energy harvesting, electrical power is transmitted from one location to another without the application of an artificial conductor. As such, there is a significant requirement for rectennas to be present in the circuit as they important in the harvesting of ambient RF power.

The rectennas should be preconditioned for efficient energy harvesting by ensuring good performance at low incident power density, relative high rectification efficiency at wide bandwidth and arbitrary polarization. The advantage of harvesting energy using rectennas is in its ability to generate unlimited energy due to it unlimited lifetime without the need of replacement as in batteries. Furthermore, the energy generated is green and therefore suitable or energy sustainability (Suh & Chang, 2002).

The term rectenna refers to a rectifying antenna that serves to combine the functions of high efficient rectifier circuits and an antennae at microwave power transmission systems. Rectennas were developed with the aim of completing the wireless power transmission system. The purpose of the rectennas is to convert electromagnetic wave into DC power after being received. Rectennas can exists in the their simplest form where they consist of multiple receiving antennae elements that enter a low pass filter circuits that is usually terminated at certain rectifying diodes.

In RF energy harvesting, a rectenna is used due to its desirable characteristics; the efficiency of energy harvesting resulting from conversion of microwave power to DC power can reach 85% and they can be designed to cater for different desirable frequencies capable of harvesting RF power that is easy to design and economical