الفهرس | Only 14 pages are availabe for public view |
Abstract Energy is one of the most important things in our life, and societies without energy are considered weak and even almost non-existent societies. Energy on the vital and economic level we find very important in our life and also we find that the coming wars in the future will be for energy, water and Wars for Earth are almost over, hence the importance of having energy. We find that the transition to 100% clean energy is realistic and close to reach. A small percentage of experts expect to reach this goal or approach it by 2050, and they have reservations in this regard, especially with the rapid growth and increasing demand for conventional energy. The renewable energy sector has recorded remarkable growth during the past years, benefiting from the technical development that contributed to the reduction in the cost of its production and from the global awareness of the need to abandon energy sources polluting the environment. This growth fuels the hope of reaching a complete dependence on renewable energies in the future, as solar photovoltaic energy is the most advanced Wind power and hydroelectric power follow, as the cost of clean energies continues to decrease and has become among the least expensive options compared to the price of electricity generated from fossil and nuclear energy. Energy harvesting from infinite sources with no adverse environmental effect can provide unlimited energy for harvesting in a way of powering an embedded system from the environment. It could be RF energy harvesting by using antennas that can be held on building or the car glass, or in any places. The ambient RF energy is harvested from surrounding sources. This thesis focuses on RF energy harvesting in which the ambient RF energy from surrounding sources, such as wireless LANs (WLANs), broadcast television signals, nearby mobile phones, and FM/AM radio signals, is captured by a receiving antenna and rectified into a usable DC voltage. A lot of researches are done to create various designs of rectenna that meet various goals for use in RF energy harvesting. Among various antennas, microstrip patch antennas are widely used because they are lightweight, are low profile, and have planar structure. In this thesis analyses in detail the technology required for wireless power transfer via radio frequency ambient energy harvesting system that can harvest energy from the ambient surroundings electromagnetic waves. The system design consists of five stages: SIW antenna (source), Taper impedance matching network, Three stages Dickson voltage multiplier circuit, Super capacitor as energy storage and Temperature sensor (load). The design and simulation of the voltage doubler circuit were performed using Agilent ADS 2014 environment, while the SIW antenna was designed using ANSYS High-Frequency Structure Simulator (HFSS). Both simulations and measurements were carried out for various input power levels from -40 dBm to 40 dBm at the specified frequency bands. The most important parameters affecting the efficiency of the system are the input power level, impedance matching, frequency band, voltage multiplier circuit, number of rectification stages and the load resistance. |