Design And Implementation Of RF Energy Harvesting System

With the depletion of traditional energy and its environmental problems, the development and utilization of new energy have got more and more attention. The increasing number of wireless products caused large radio frequency(RF) energy, particularly in densely populated cities. If the energy can be effectively and efficiently captured, then it can become widely available microwave energy for human life.Because of its promising prospect, the RF energy haresting attracted a great deal of attention from academia and industry.By reading a lot of related papers, we studied its theories and implemented a dual-band RF energy harvesting system working at GSM 900 MHz and Wi Fi 2.4GHz.The main work of this thesis includes:1. A simple dual-band patch antenna that radiates at 940 MHz and 2.45 GHz is designed and inplemented. The patch antenna is designed with meander slot and shorting probe to increase the current path and reduce the resonant frequency. After simulation and fabrication, we tested the prototypes for verification, and analyzed the reasons for the differences.2. By adding two resonant inductors to a conventional voltage doubler circuit, a dual-band rectifier is also designed. The resonant frequency of the rectifier can be tuned independently by tuning values of the two resonant inductors. Combined with S-parameter, parameter sweeps, harmonic balance analysis and other functions of ADS we analyze the effects on the circuit caused by the resonant inductors, input power, signal frequency, load size and other factors. Finally, we test the prototype, and give the reasons for its low efficiency.3. In order to improve the gain of the receiving antenna, two 2 × 2 array antennas with perating frequencies at 900 MHz and 2.44 GH are designd. Due to its size and cost, we only fabricate and measured the 2.4GHz patch array.