The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This study proposes a simple method for creating flat beam patterns in a near-field. In radio-wave transmission, the near-field beam efficiency of the beam-type wireless power transfer (WPT) system theoretically reaches 100%, but the beam pattern is not flat in the near field. In real beam-type WPT systems, the total beam efficiency (DC-RF-transmission, beam efficiency, and RF-DC conversion) can be...
The input load characteristics of a DC motor vary with input powers. The conversion efficiency of a rectifying circuit is strongly affected by the connected load. Therefore, to efficiently drive a DC motor using microwave power transfer (MPT), it needs to improve the efficiency-load characteristics of the rectifying circuit. We design a compact power-receiving device which mounts antennas, rectifiers...
Rectenna, rectifying antenna, is one of key technologies of a wireless power transfer and an energy harvesting from broadcasting waves. The rectenna is composed of an antenna and a rectifying circuit with diodes to convert radio frequency (RF), for example, GHz band, to direct current (DC). The RF-DC conversion efficiency of the rectenna is decided by characteristics of the diode, especially voltage-current...
Various wireless power transmissions (WPT) are applied to charge an electric vehicle (EV). An inductive coupling WPT and resonance coupling WPT are often used. We proposed a WPT via microwave (microwave power transmission; MPT) for the wireless charging of the EV. We, Kyoto University, developed two types of the wireless charging of the EV with microwave. One is short distance system which has been...
Microwave Power Transmission (MPT) can be applied to a greater number of applications provided that higher frequency MPT systems are developed. In particular, we need high efficiency rectennas at higher frequencies. We developed a monolithic microwave integrated circuit (MMIC) rectenna with a resonant frequency of 24 GHz, with dimensions of 1 mm × 3 mm, and whose maximum RF-DC conversion efficiency...
We improved class-F load rectennas at 24GHz which optimal load and optimal input power were different from the designed ones. We focused on the class-F load which is the most important point in class-F load rectennas. Through analysis of electromagnetic field, we clarified that we could simulate accurately with a circuit analysis simulator when the discontinuity in a microstrip line was small and...
Open-ring resonator coupling is used for the wireless power transmission through 1.6mm thick epoxy-glass plate. Microwave signal is emitted from one circuit board where an open-ring resonator is placed and the signal is received by another board with also an open-ring resonator and GaN Schottky barrier diode. At 2.3 GHz, RF to DC conversion efficiency of 37.1 % is obtained at the input power of 3...
We designed and fabricated the rectennas which use class-F load as an output filter in order to develop highly efficient rectennas at 24GHz and 60GHz. We also fabricated conventional rectennas which use a capacitor as an output filter, and compared the efficiency of class-F load rectennas with that of capacitor rectennas. We selected the diode which can produce high efficiency even at high frequency,...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.