Antenna Characterization for Wireless Power
Antenna Characterization for Wireless Power-Transmission System Using Near-Field Coupling
Wireless power transmission is the transmission of electrical energy from a power source to an electrical load without man-made conductors. Wireless transmission is useful in cases where interconnecting wires are inconvenient, hazardous, or impossible. So a study was made on the investigation of wireless power transmission by near-field coupling from the view point of the antennas. Mainly the antennas are of two types - dipole and loop antennas – and were used as the transmitting antenna and the receiving antenna for electrical near-field coupling and for magnetic near-field coupling, respectively. The relationships among the power-transmission efficiency and the antennas ' geometries, the antennas ' electrical sizes, the impedance matching of the antennas, and the ohmic losses in the antennas and the impedance-matching circuits were clarified. This technology has been widely applied, from the wireless charging of electronic devices to huge projects, such as the solar-power satellite system. The most important challenge is to maintain higher power-transmission efficiency over longer transmission distances which was strictly defined as the ratio of the received power at the receiving antenna and the input power at the transmitting antenna. Several observations were obtained, demonstrating the influence on the power-transmission efficiency of the impedance matching and ohmic losses in the wireless power-transmission system associated with near-field coupling. A wireless power-transmission system was numerically analysed by using canonical methods, including a dipole system and a loop system, the relationships among the power-transmission efficiency and the antenna geometries, distance between antennas, sizes and ohmic losses in the antennas and matching circuits. These results and observations can provide theoretical insight into
Wireless power transmission is the transmission of electrical energy from a power source to an electrical load without man-made conductors. Wireless transmission is useful in cases where interconnecting wires are inconvenient, hazardous, or impossible. So a study was made on the investigation of wireless power transmission by near-field coupling from the view point of the antennas. Mainly the antennas are of two types - dipole and loop antennas – and were used as the transmitting antenna and the receiving antenna for electrical near-field coupling and for magnetic near-field coupling, respectively. The relationships among the power-transmission efficiency and the antennas ' geometries, the antennas ' electrical sizes, the impedance matching of the antennas, and the ohmic losses in the antennas and the impedance-matching circuits were clarified. This technology has been widely applied, from the wireless charging of electronic devices to huge projects, such as the solar-power satellite system. The most important challenge is to maintain higher power-transmission efficiency over longer transmission distances which was strictly defined as the ratio of the received power at the receiving antenna and the input power at the transmitting antenna. Several observations were obtained, demonstrating the influence on the power-transmission efficiency of the impedance matching and ohmic losses in the wireless power-transmission system associated with near-field coupling. A wireless power-transmission system was numerically analysed by using canonical methods, including a dipole system and a loop system, the relationships among the power-transmission efficiency and the antenna geometries, distance between antennas, sizes and ohmic losses in the antennas and matching circuits. These results and observations can provide theoretical insight into
References: : Qiang Chen, Kazuhiro Ozawa, Qiaowel Yuan and Kunio Sawaya