The Wireless Energy Transfer recharging system based on the ultra-high frequency by using Yagi-Uda directional antenna

In the near future, the Wireless Energy Transfer (WET) will be widely used, especially for electronics recharging in the human organ implantations. WET has been researched intensively by some researchers, but the low efficient energy transfer is still a problem. In order to figure out the efficiency of the energy transfer, the experiment had been conducted in Laboratory of Sensor and Telecontrol Systems. The complexities of the measurement system setup and assessment of the sufficient energy both transmitter and receiver will also be discussed. The experiment results deliver the new design of the WET, empiric data of the energy transfer, and the sufficient antenna model as well. In this research, The UHF transmitter generated radio frequency with output energy of 39.00-watt energy source. The range of various frequencies in this paper is 400 MHz to 489 MHz and the SWR is 1.2. The transmitter unit and the antenna were connected with the 50 ohm-coaxial cable. In order to transfer the energy, the transmitter system consisting Yagi-Uda model antenna was applied. The results show that the efficiency maximum of the measured energy transfer is 0.36%. In our investigations, the efficiency of the result also depends on the polarity of the Yagi-Uda Antenna used in the experiment. According to the results, the angle that the maximum energy transferred is 60°, on the contrary, the angle of 150° gives the lowest efficiency results. We found that the distance between the transmitter and receiver antenna contribute significantly to the amount of energy transferred from the system. In this case, the energy can be calculated from the current and voltage measurement. The energy transfer versus distance relationship shows that a specific trend was obtained. This specific trend seems are affected by the antenna characters used in the experiment. Based on the experiment results, the wireless energy transfer could be done by utilizing UHF radio wave. Even though the efficiencies were still relatively low, but it can be used for some specific purposes in the example, in the electronic human organ implant recharging and applicable for the general electronic devices in the special areas. This experiment data are very useful for the scientists, practicing who work in the WET research field.