Kanazawa Institute of Technology: Power transmission by microwave wireless: World’s highest power conversion efficiency
Nobel Prize in Physics Professor Hiroshi Amano:
A research group led by Professor Hiroshi Amano, who won the Nobel Prize in Physics, has developed “a new technology that can efficiently transmit power wirelessly.”
Conventional wireless power transfer technology:
The technology to send power wirelessly without using electric wires has already been put to practical use in smartphone chargers and the like.
However, the problems are that the amount of power that can be sent is small and the distance is short.
This microwave transmission technology:
The research group worked on the development of new technologies using microwaves.
As a result, we have succeeded in “making the power conversion efficiency during power transmission the highest in the world.”
Use gallium nitride:
Uses gallium nitride, a material for blue light-emitting diodes that won the Nobel Prize in Physics.
With gallium nitride, we have “developed a component that can receive three times as much power as before wirelessly.”
10 watt class power transmission radio:
The research group wants to establish a “system that wirelessly sends 10 watt class power” by 2022.
If it is put into practical use,
Send power to the drone,
It can be supplied when needed even in places where there are no wires,
It is also possible to collect data on river water levels, etc.
NHK news
https://www3.nhk.or.jp/news/html/20200923/k10012631391000.html
Wireless power transmission using microwaves (5.8GHz):
-Achieved the world’s highest power conversion efficiency-
Power transmission to drones that fly long distances,
Highly efficient power transmission to equipment, etc.
Accelerate research toward power transmission to the ground by space solar power generation
2020.9.23
Department of Electrical and Electronic Engineering, Faculty of Engineering, Kanazawa Institute of Technology
Professor Kenji Ito,
Research group of Researcher Naoki Sakai:
Achieved “92.8%, the world’s highest power conversion efficiency” for microwave (5.8GHz) and power receiving rectenna (at 1W input).
* What is Rectenna?
(Rectenna): An antenna with a rectifier.
This power receiving rectenna:
The configuration has been changed from the conventional “power receiving antenna + circuit + diode” configuration.
This time, a “power receiving antenna + diode” configuration has been adopted to reduce circuit loss.
The power conversion efficiency from microwaves to direct current has been increased to the limit.
The shape of the power receiving antenna has been improved, and all conventional circuit functions have been realized with the power receiving antenna.
Semiconductor for rectification this time:
As a rectifying semiconductor, “GaAs diode with good microwave characteristics developed by Mitsubishi Electric” is applied to obtain high efficiency.
Significance of results:
This time, we have achieved high efficiency with 1W power reception.
Next time, we will work on establishing high-efficiency power receiving technology of 10W.
In this research, we have established a technology that minimizes the loss in the power receiving rectenna (power receiving antenna + rectifier circuit) and realizes the maximum efficiency.
High withstand voltage GaN, HEMT type diode:
To establish high-efficiency power receiving technology of 10W
We plan to use a high-voltage gallium-nitride (GaN) HEMT type diode being developed by Nagoya University / Nagoya Institute of Technology / Mitsubishi Electric.
KIT Kanazawa Institute of Technology