| （英） |
We are participating in the research and development of evaluation methods for spatial transmission Wireless Power Transmission (WPT) equipment. In this report, we focus on the development of the antenna part for the Over The Air (OTA) evaluation and present the results of the development and evaluation.
This R&D focused on two frequency bands, 920 MHz and 5.7 GHz, and this report describes the development of a transmitter for measurement evaluation of the WPT system and antennas required for OTA evaluation.
The 5.7-GHz band WPT system requires variable beam control on the transmitter side and an EIRP of 70 dBm. Therefore, we have developed a 5.7-GHz-band phase-controlled beamforming antenna with a water-cooled heat dissipation mechanism.
Since the WPT system is an integrated device including a transmitter source, it is necessary to use a fixed antenna reference method to measure the phase of the radiated electric field. In the 920 MHz band, the reference antenna is a leaky wave antenna with a maximum gain of -11 dBi. A circularly polarized patch antenna was developed considering the influence of a rotating stand (made of metal) where the reference antenna is installed in the 5.7 GHz band.
This work was supported by the Strategic Innovation Program (SIP) "Energy System for IoE Society" of the Council for Science, Technology, and Innovation (JST), Cabinet Office, Government of Japan. |