Nihon Dengyo Kosaku and Volvo Technology Japan wirelessly transmit 10kW of electricity 4 meters using rectification of microwave signals
Tech-On. Nihon Dengyo Kosaku and Volvo Technology Japan have demonstrated the wireless transmission of 10kW of electricity a distance of 4 meters using a prototype high-efficiency rectenna—a microwave rectifying antenna that converts microwave energy into direct-current electricity.
The 10 kW rectenna was made by combining eight rectennas the output of which is about 1.3 kW each; overall efficiency of the conversion is about 84%. Dengyo announced its first rectenna product last year.
The output power per area is 3.2kW/m2 or higher, which Dengyo claims is the “world’s highest output.” The frequency of the microwave is 2.45GHz.
Volvo Technology Japan was established by Sweden-based AB Volvo in 2012 in Tokyo as its R&D base in Asia. The Volvo Group plans to apply the newly-developed wireless power transmission technology to commercial vehicles such as buses and trucks, Volvo Technology Japan said.
The rectification of microwave signals for DC power has been researched and developed for decades for a wide range of applications, especially for satellites. (Japan is exploring the possibility of developing a Space Solar Power Station/Satellite (SPS) that would use rectennas for power transmission to Earth. Earlier post.)
The basic rectenna was patented in 1969 by William Brown.